Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/07/15
AREA FORECAST DISCUSSION
NWS TUCSON AZ
235 PM MST TUE MAY 5 2015
.SYNOPSIS...THERE IS A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
MAINLY NORTHEAST OF TUCSON INTO THIS EVENING. DRY CONDITIONS WILL
THEN PREVAIL WEDNESDAY INTO EARLY NEXT WEEK. THE EXCEPTION WILL BE A
FEW SHOWERS AND THUNDERSTORMS ACROSS THE WHITE MOUNTAINS SATURDAY.
EXPECT BREEZY TO WINDY CONDITIONS DURING THE LATTER PART OF THE
WEEK. BELOW NORMAL DAYTIME TEMPERATURES WILL OCCUR INTO SATURDAY
FOLLOWED BY A SIGNIFICANT WARMING TREND EARLY NEXT WEEK.
&&
.DISCUSSION...THE SYSTEM THAT BROUGHT SHOWERS AND THUNDERSTORMS TO
THE AREA YESTERDAY AND LAST NIGHT WILL CONTINUE TO INFLUENCE THE
WEATHER TODAY. RESIDUAL MOISTURE COMBINED WITH DAYTIME HEATING AND
SOME SUPPORT FROM THE UPPER LOW WILL RESULT IN A FEW SHOWERS AND
THUNDERSTORMS YET THIS EVENING. LATEST HRRR MODEL SOLUTION KEPT MOST
OF THIS ACTIVITY NORTHEAST OF THE TUCSON METRO THIS EVENING.
ALTHOUGH THE MODEL DEPICTED VERY SPOTTY ACTIVITY...SO WILL JUST KEEP
LOW POP VALUES IN THE FORECAST FOR NOW. OTHERWISE...MODELS EJECT THE
SYSTEM NORTHEAST INTO THE CENTRAL PLAINS BY TOMORROW MORNING
RESULTING IN A BREAK IN THE RAIN CHANCES. HOWEVER...ANOTHER SYSTEM
WAS PROGGED TO DROP SOUTH ALONG THE INTERIOR WEST COAST INTO CENTRAL
CALIFORNIA ON THURSDAY. THIS NEXT SYSTEM WILL BRING STRONG AND GUSTY
WINDS TO THE AREA AS EARLY AS TOMORROW AFTERNOON BUT MORE SO ON
THURSDAY. MODELS TRACK THIS SYSTEM THROUGH NORTHERN ARIZONA FRIDAY
INTO SATURDAY. FOR NOW...THE BEST CHANCE OF RAIN WILL BE ACROSS
NORTHERN ARIZONA INTO THE WHITE MOUNTAINS MAINLY ON SATURDAY.
THEREAFTER...A RIDGE OF HIGH PRESSURE WAS PROGGED TO BUILD OVER THE
AREA BEFORE ANOTHER SYSTEM APPROACHES THE SOUTHERN CALIFORNIA COAST
EARLY NEXT WEEK. DAYTIME TEMPERATURES WILL REMAIN BELOW NORMAL THIS
WEEK.
&&
.AVIATION...VALID THRU 07/00Z. SCATTERED SHOWERS AND THUNDERSTORMS
WILL BE POSSIBLE OVER THE WHITE MOUNTAINS NE OF KSAD INTO THIS
EVENING. GUSTY AFTERNOON WINDS WILL DIMINISH TO NORMAL DIURNAL
TRENDS AFTER SUNSET...GENERALLY LESS THAN 10 KTS THROUGH THE
MORNING. LOW AND MID LEVEL CLOUDS DIMINISHING TONIGHT...WITH SCT
HIGH CLOUDS MOVING IN LATE TONIGHT INTO WEDNESDAY MORNING. EXPECT
STRONGER WINDS WEDNESDAY...15 TO 20 KTS GUSTING TO AROUND 30 KTS. AN
EARLIER START TO WINDS WEDNESDAY...PICKING UP AROUND 16Z AT KSAD AND
KDUG...17Z AT KTUS. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
&&
.FIRE WEATHER...A CHANCE OF SHOWERS AND THUNDERSTORMS CONTINUES
MAINLY EAST OF TUCSON TODAY AND ACROSS THE WHITE MOUNTAINS INTO THIS
EVENING. DRY CONDITIONS WILL THEN PREVAIL LATE TONIGHT.
A LOW PRESSURE SYSTEM WILL STRENGTHEN NORTHWEST OF THE AREA
WEDNESDAY INTO FRIDAY. THIS SYSTEM WILL PRODUCE BREEZY CONDITIONS
WEDNESDAY AFTERNOON FOLLOWED BY BREEZY TO WINDY CONDITIONS THURSDAY
AND FRIDAY. HOWEVER...DAYTIME MINIMUM RELATIVE HUMIDITIES AND FUEL
MOISTURE WILL BE MARGINAL AT BEST TO PRODUCE CRITICAL FIRE
CONDITIONS. A FEW SHOWERS AND THUNDERSTORMS MAY THEN OCCUR ACROSS
THE WHITE MOUNTAINS SATURDAY AS THE LOW PRESSURE SYSTEM MOVES NORTH
OF THE AREA. EXPECT LESS WIND THIS WEEKEND ALTHOUGH SOME AFTERNOON
GUSTINESS WILL OCCUR DUE TO DAYTIME HEATING.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS TUCSON AZ
853 AM MST TUE MAY 5 2015
.SYNOPSIS...THERE IS A CHANCE OF SHOWERS AND THUNDERSTORMS MAINLY
NORTHEAST OF TUCSON INTO THIS EVENING. DRY CONDITIONS WILL THEN
PREVAIL WEDNESDAY INTO EARLY NEXT WEEK. THE EXCEPTION WILL BE A FEW
SHOWERS AND THUNDERSTORMS ACROSS THE WHITE MOUNTAINS SATURDAY.
EXPECT BREEZY TO WINDY CONDITIONS DURING THE LATTER PART OF THE
WEEK. BELOW NORMAL DAYTIME TEMPERATURES WILL OCCUR INTO SATURDAY
FOLLOWED BY A SIGNIFICANT WARMING TREND EARLY NEXT WEEK.
&&
.DISCUSSION...THE UPPER LOW THAT BROUGHT SHOWERS AND THUNDERSTORMS
TO THE AREA YESTERDAY AND LAST NIGHT WILL CONTINUE TO INFLUENCE THE
WEATHER TODAY. RESIDUAL MOISTURE COMBINED WITH DAYTIME HEATING AND
SOME SUPPORT FROM THE UPPER LOW WILL RESULT IN MORE SHOWERS AND
THUNDERSTORMS TODAY. LATEST HRRR MODEL SOLUTION KEEPS MOST OF THIS
ACTIVITY JUST EAST AND NORTHEAST OF THE TUCSON METRO THIS AFTERNOON
AND EVENING. THEREAFTER...MODELS EJECT THIS UPPER LOW NORTHEAST INTO
THE CENTRAL PLAINS BY TOMORROW MORNING RESULTING IN A BREAK IN RAIN
CHANCES. HOWEVER...ANOTHER SYSTEM WAS PROGGED TO DROP SOUTH ALONG
THE INTERIOR WEST COAST INTO CENTRAL CALIFORNIA ON THURSDAY. THIS
NEXT SYSTEM WILL BRING STRONG AND GUSTY WINDS TO THE AREA AS EARLY
AS TOMORROW BUT MORE SO THURSDAY. CURRENT FORECAST LOOKED ON
TRACK...SO NO UPDATES NECESSARY THIS MORNING. PLEASE REFER TO THE
ADDITIONAL SECTIONS FOR MORE DETAILS.
&&
.AVIATION...VALID THRU 06/18Z.
SCATTERED -TSRA/-SHRA WILL PREVAIL TODAY MAINLY ACROSS THE WHITE
MOUNTAINS NE OF KSAD. EXPECT ISOLATED -TSRA/-SHRA FURTHER SWWD TO
NEAR THE CATALINA/RINCON MOUNTAINS NEAR KTUS. DRY CONDITIONS WILL
THEN PREVAIL LATE TONIGHT AND EARLY WEDNESDAY MORNING. OTHERWISE...
IMPROVING CONDITIONS THIS PERIOD AS A LOW PRESSURE TROUGH OVER
ARIZONA THIS MORNING MOVES INTO NEW MEXICO THIS EVENING. CLOUDS WILL
DECREASE FROM WEST TO EAST THIS AFTERNOON WITH CLEAR SKIES OR MOSTLY
CLEAR SKIES EARLY WEDNESDAY MORNING. SURFACE WIND THIS AFTERNOON
WILL BE WLY/NWLY 12-18 KTS WITH GUSTS OF 20-25 KTS. SURFACE WIND
WILL BE MAINLY LESS THAN 10 KTS AT OTHER TIMES. AVIATION DISCUSSION
NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...A CHANCE OF SHOWERS AND THUNDERSTORMS CONTINUES
MAINLY EAST OF TUCSON TODAY...AND A FEW SHOWERS MAY LINGER ACROSS
THE WHITE MOUNTAINS THIS EVENING. DRY CONDITIONS WILL THEN PREVAIL
LATE TONIGHT.
A LOW PRESSURE SYSTEM WILL STRENGTHEN NORTHWEST OF THE AREA
WEDNESDAY INTO FRIDAY. THIS SYSTEM WILL PRODUCE BREEZY CONDITIONS
WEDNESDAY AFTERNOON FOLLOWED BY BREEZY TO WINDY CONDITIONS THURSDAY
AND FRIDAY. HOWEVER...DAYTIME MINIMUM RELATIVE HUMIDITIES AND
FUEL MOISTURE WILL BE MARGINAL AT BEST TO PRODUCE CRITICAL FIRE
CONDITIONS. A FEW SHOWERS AND THUNDERSTORMS MAY THEN OCCUR ACROSS
THE WHITE MOUNTAINS SATURDAY AS THE LOW PRESSURE SYSTEM MOVES NORTH
OF THE AREA. EXPECT LESS WIND THIS WEEKEND ALTHOUGH SOME AFTERNOON
GUSTINESS WILL OCCUR DUE TO DAYTIME HEATING.
&&
.PREV DISCUSSION...UPPER LEVEL TROUGH WAS OVER THE WRN CONUS THIS
MORNING WITH A WEAK LOW PRESSURE SYSTEM CENTERED OVER NERN ARIZONA.
THIS LOW PRESSURE SYSTEM WILL FILL AND MOVE EWD INTO THE CENTRAL
ROCKIES THIS AFTERNOON. THE NEXT UPSTREAM COLD UPPER LOW WILL DIG
OVER SRN BRITISH COLUMBIA AND THE PACIFIC NW.
MEANWHILE...ADEQUATE MOISTURE WILL PROVIDE A CHANCE OF SHOWERS/TSTMS
THIS MORNING ACROSS THE WHITE MOUNTAINS...AND A SLIGHT CHANCE OF
SHOWERS/TSTMS WILL OCCUR FURTHER SWWD TO NEAR THE TUCSON METRO AREA.
DRIER AIR WILL THEN SPREAD EWD ACROSS THE AREA THIS AFTERNOON INTO
TONIGHT. A CHANCE OF SHOWERS/TSTMS CONTINUES THIS AFTERNOON ACROSS
THE WHITE MOUNTAINS WITH ISOLATED SHOWERS/TSTMS ACROSS GRAHAM
COUNTY. ANY SHOWERS/TSTMS THIS EVENING SHOULD BE CONFINED TO THE
WHITE MOUNTAINS. DRY CONDITIONS WILL THEN PREVAIL LATE TONIGHT.
THE FLOW ALOFT WILL BECOME INCREASINGLY SWLY WED AS THE COLD UPPER
LOW PRESENTLY OVER SRN BRITISH COLUMBIA AND THE PACIFIC NW DIGS INTO
THE GREAT BASIN. A TIGHTENING MID-LEVEL GRADIENT AHEAD OF THIS
SYSTEM WILL PRODUCE SOME BREEZINESS WED AFTERNOON. EXPECT BREEZY TO
WINDY CONDITIONS THUR-FRI AS THE LOW PRESSURE SYSTEM CONTINUES TO
DEEPEN NW OF THE AREA. HAVE INTRODUCED A SLIGHT CHANCE OF SHOWERS/
TSTMS ACROSS THE WHITE MOUNTAINS SAT AS THE UPPER LOW FILLS AND
MOVES NORTH OF THE AREA. OTHERWISE...DRY CONDITIONS WILL PREVAIL SAT-
MON. EXPECT LESS WIND THIS WEEKEND...ALTHOUGH SOME AFTERNOON GUSTS
WILL OCCUR DUE TO DAYTIME HEATING.
BELOW NORMAL DAYTIME TEMPS WILL OCCUR THRU SATURDAY FOLLOWED BY A
WARMING TREND SUN-MON.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
954 PM MDT WED MAY 6 2015
.UPDATE...
ISSUED AT 940 PM MDT WED MAY 6 2015
HAVE INCREASED THE PRECIPITATION COVERAGE THROUGH TONIGHT AS
THERE CONTINUES TO BE SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS
UPSTREAM. IT APPEARS THAT THERE WILL CONTINUE TO BE WEAK EMBEDDED
DISTURBANCES IN THE SOUTHWEST FLOW OVER THE FORECAST AREA. THIS
WILL BE ENOUGH TO KEEP ISOLATED TO SCATTERED SHOWERS AT TIMES
THROUGHOUT THE NIGHT...GRADUALLY WINDING DOWN TOWARDS MORNING. THE
SOUTHERN PORTION HAS CONTINUED TO BE MORE ACTIVE THAN EXPECTED
WITH ENERGY STREAMING OVER THE FOUR CORNERS AT THIS TIME. THIS
SHOULD PERSIST FOR THE NEXT FEW HOURS. THEREFORE THE FORECAST WILL
SEE THE BIGGEST CHANGES THERE.
&&
.SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT)
ISSUED AT 309 PM MDT WED MAY 6 2015
THE STRONG LOW THAT MOVED OVER THE AREA LAST NIGHT AND THIS
MORNING WILL CONTINUE MOVING INTO THE HIGH PLAINS TONIGHT.
NW AND CENTRAL CO AND NE UT WILL BE BENEATH THE NW FLOW ALOFT
ON THE WEST SIDE OF THE STORM...WHERE UNSTABLE AND MOIST
CONDITIONS WILL CONTINUE TO PRODUCE RAIN SHOWERS AND THUNDERSTORMS
OVER MUCH OF THE AREA. A FEW STORMS HAVE BEEN STRONG ENOUGH TO
PRODUCE SMALL HAIL AND HEAVY RAIN. A WEAK SHORTWAVE TROUGH MOVING
OVER NORTHWEST CO AND NE UT WILL ALSO AS SOME SUPPORT FOR
CONVECTION UNTIL ABOUT 03Z THIS EVENING. SUBSIDENCE AND GRADUALLY
DRIER AIR WILL FILTER INTO EASTER UT...AND NORTHWEST AND CENTRAL
CO AFTER MIDNIGHT. OVER SW CO...THE HRRR AND NAM12 SHOW ANOTHER
WEAK SHORTWAVE WILL BRING INCREASING CLOUDS AND ISOLATED
PRECIPITATION LATE TONIGHT.
THURSDAY MORNING...IN SOUTH FLOW A WEAK WAVE WORKS THROUGH THE
FOUR CORNERS REGION. AVAILABLE MOISTURE WILL BE DIMINISHING THERE
SO ONLY ISOLATED SHOWERS ARE FORECASTED ACROSS THE SOUTH FAVORING
THE SAN JUANS. DEEPER MOISTURE REMAINS ACROSS THE NORTH THURSDAY
ALONG WITH SOME WEAK FRONTAL FORCING. MARGINAL AFTERNOON
INSTABILITY WILL LIMIT THUNDERSTORM COVERAGE MAINLY OVER MTNS
NORTH OF I-70.
THURSDAY NIGHT DRIER SW FLOW INVADES LIMITING NIGHTTIME SHOWERS
TO NEAR THE CONTINENTAL DIVIDE. TEMPERATURES REMAIN NEAR NORMAL.
THE NEXT STRONGER PACIFIC LOW SINKS THROUGH CALIFORNIA ON THURSDAY
THEN BEGINS TO AMBLE INLAND THURSDAY NIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 309 PM MDT WED MAY 6 2015
A HIGHLY AMPLIFIED PROGRESSIVE PATTERN CONTINUES THROUGH THESE
PERIODS. ONE STRONG UPPER LOW WILL PASS ON SATURDAY BRINGING A
BLAST OF NORTHERN AND MOUNTAIN SNOW. TWO OTHER TROUGHS CURRENTLY
ARE TIMED TO PASS MID TO LATE NEXT WEEK.
FRIDAY THE UPPER LOW WITH A MODIFYING BUT IMPRESSIVE -26C COLD
CORE WORKS NORTH OF LAS VEGAS TO SOUTHCENTRAL UTAH FRIDAY NIGHT
AND THROUGH THE FORECAST AREA ON SATURDAY. THE THERMAL RIDGE
BLOSSOMS OVER THE FORECAST AREA FRIDAY AND HAVE RAISED
TEMPERATURES CLOSER TO THE WARMER NAM GUIDANCE. A 70KT JET NOSE
POKES INTO SE UTAH IN THE AFTERNOON AND RAKES THE SOUTH OVERNIGHT.
COOL ADVECTION ALOFT BEGINS TO DESTABILIZE BUT AVAILABLE MOISTURE
IS LIMITED AND MAINLY ACROSS THE NORTH.
SATURDAY THE POTENTIAL VORTICITY CENTER RAKES THE NORTH AS THE
JET WRAPS UP THE FRONT RANGE. FRONTAL FORCING SEEN IN THE PARK
RANGE BY THE AFTERNOON. THE BEST SHOWER COVERAGE WILL BE OVER THE
NORTHERN MOUNTAINS BUT WILL EXTEND INTO THE CENTRAL CO MTNS. SNOW
LEVELS DROP TO AROUND 8KFT...AND WILL BRIEFLY BE LOWER IN
STRONGER CONVECTION. THE LOW LIFTS THROUGH THE NORTHERN PLAINS
SATURDAY NIGHT THROUGH SUNDAY. WRAP- AROUND MOISTURE WILL CONTINUE
TO PRODUCE SHOWERS FAVORING THE NORTH. SUNDAY...SNOW LEVELS LOWER
INTO THE NORTHERN VALLEYS WITH 700MB TEMPS AT -4C THERE.
SIGNIFICANT SNOWFALL IS EXPECTED FOR THIS WEEKEND FOR THE EASTERN
UINTAS AND THE COLORADO MOUNTAINS FROM WYOMING DOWN INTO THE NW
SAN JUANS. TRAVEL THROUGH THESE MOUNTAINS COULD BE HAZARDOUS THIS
WEEKEND. COLDER THAN NORMAL TEMPERATURES EXPECTED ACROSS THE
REGION THROUGH SUNDAY NIGHT. HIGH VALLEY FREEZES ARE POSSIBLE.
MONDAY WARM ADVECTION BEGINS AS A RIDGE BUILDS IN FROM THE WEST.
FLOW ALOFT QUICKLY SWITCHES BACK TO SW AND INCREASES INTO THE NEW
WEEK AS THE NEXT TROUGH WORKS INTO THE PACIFIC NW ON TUESDAY AND
THE GREAT BASIN ON WEDNESDAY. AN ASSOCIATED ZONAL JET FROM CENTRAL
CALIFORNIA INTRUDES INTO THE NORTHERN-CENTRAL FORECAST AREA ON
WEDNESDAY BEGINNING THE CHANCE OF MAINLY RAIN SHOWERS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY AFTERNOON)
ISSUED AT 445 PM MDT WED MAY 6 2015
SCATTERED SHOWERS AND THUNDERSTORMS BY SUNSET WILL BECOME LIMITED
TO THE MOUNTAINS IN THE VICINITY OF THE CONTINENTAL DIVIDE AND
ALONG THE WYOMING BORDER. TAF SITES KEGE KASE MAY SEE BRIEF MVFR
CIGS IN -TSRA UNTIL 03Z. SHOWERS BECOME MORE ISOLATED IN COVERAGE
AFT 06Z. AFT 09Z SCT -SHRA ISOLATED -TSRA WILL DEVELOP OVER SW
COLORADO. TAF SITES KDRO KTEX MAY SEE BRIEF MVFR CIGS IN -SHRA.
AFT 15Z SCT MAINLY MTN -TSRA EXPECTED MAINLY NORTH OF HIGHWAY 50
CORRIDOR. TAF SITES KASE KEGE MAY SEE BRIEF MVFR CIGS IN
-TSRA/-SHRA.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...EH
SHORT TERM...CC/JOE
LONG TERM...JOE
AVIATION...JOE
AREA FORECAST DISCUSSION
NWS PUEBLO CO
915 PM MDT WED MAY 6 2015
.UPDATE...
ISSUED AT 915 PM MDT WED MAY 6 2015
INCREASED POPS FOR TONIGHT ACROSS THE CONTDVD WITH EMBEDDED SHORT
WAVE LIFTING OUT OF THE FOUR CORNERS AREA.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 345 PM MDT WED MAY 6 2015
CURRENTLY...UPPER LOW PUSHING SLOWLY INTO WRN NEB THIS
AFTERNOON...WHILE WEAKER SHORT WAVE ENERGY WAS DRIFTING NORTH INTO
SOUTHERN COLORADO FROM NM. WITH LACK OF MUCH BL/SURFACE WLY FLOW AND
MOIST GROUND...DEWPOINTS HAVE HELD IN THE MID TO UPPER 40S ACROSS
THE I-25 CORRIDOR AND IN THE LOWER 50S FARTHER EAST NEAR THE KS
BORDER. MESO-ANALYSIS SUGGESTS MIXED LAYER CAPES OVER 1000 J/K
ACROSS THE PLAINS ALONG THE ARKANSAS RIVER THIS AFTERNOON WHERE
SKIES HAVE CLEARED...WITH VALUES 500-1000 J/K FARTHER WEST OVER THE
MOUNTAINS AND VALLEYS. STRONGEST STORMS SO FAR TODAY HAVE BEEN OVER
EL PASO COUNTY...THOUGH ADDITIONAL CELLS HAVE BEGUN DEVELOPING
SOUTHWARD ALONG AND WEST OF I-25 AS OF 2030Z.
TONIGHT...LATEST HRRR BRINGS CONVECTION OFF THE MOUNTAINS AND ACROSS
THE PLAINS LATE THIS AFTERNOON AND EARLY THIS EVENING AS WEAK NM
SHORTWAVE MOVES NORTH...WITH PERHAPS A LOOSELY ORGANIZED LINE
DEVELOPING 00Z-01Z AS STORMS REACH THE KS BORDER. SHEAR IS FAIRLY
WEAK...SO EXPECT MAINLY BRIEF HEAVY RAIN AND SMALL HAIL WITH CELLS
INTO THE EVENING. NAM/GFS END MOST CONVECTION THIS EVENING...WHILE
HRRR DEVELOPS SOME WEAK SHOWERS OVER THE EASTERN MOUNTAINS AND EL
PASO COUNTY 06Z-07Z. WILL GRADUALLY TAPER OFF POPS DURING THE
EVENING...KEEPING SOME LOW CHANCES AFTER MIDNIGHT MAINLY OVER THE
MOUNTAINS AND NORTH OF THE ARKANSAS RIVER. WEAK COLD FRONT WILL DROP
SOUTH THROUGH THE PLAINS LATE TONIGHT...WITH A GRADUALLY SHIFT TO N-
NE WINDS ALONG AND EAST OF I-25 BY SUNRISE WED. MAY SEE SOME LOWER
CLOUDS BEHIND THE BOUNDARY EARLY WED MORNING...ESPECIALLY NEAR THE
KS BORDER WHERE LOW LEVEL MOISTURE WILL BE DEEPER.
THURSDAY...OLD UPPER TROUGH LIFTS INTO THE NORTHERN HIGH PLAINS
WHILE NEW UPPER LOW TAKING SHAPE ACROSS CENTRAL CALIFORNIA. AS A
RESULT...BROAD SOUTHWEST FLOW WILL GRADUALLY STRENGTHEN ACROSS THE
AREA...WHILE SURFACE COLD FRONT BECOMES STATIONARY ALONG THE NM
EARLY IN THE DAY BEFORE LIFTING NORTHWARD TO SOMEWHERE BETWEEN THE
THE ARKANSAS RIVER AND PALMER DIVIDE BY EVENING. BEST BET FOR STORMS
WILL BE NORTH OF THE BOUNDARY...WHERE LOW LEVEL MOISTURE POOLS AND
CAPES CLIMB TOWARD 1000 J/KG. SEVERE THREAT LOOKS FAIRLY LOW AS 0-
6KM SHEAR STAYS BELOW 40 KTS...THOUGH A COUPLE STRONG STORMS WITH
BRIEF HEAVY RAIN AND SMALL HAIL WILL BE LIKELY. ELSEWHERE...ISOLATED
TO SCATTERED CONVECTION LOOKS POSSIBLE...THOUGH INSTABILITY WILL BE
FAIRLY LOW...LIMITING STORM INTENSITY. MAX TEMPS WILL COOL JUST
SLIGHTLY ACROSS THE PLAINS BEHIND THE FRONT...WITH LITTLE CHANGE
ELSEWHERE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 345 PM MDT WED MAY 6 2015
...ACTIVE PATTERN THROUGH AT LEAST SUNDAY...
.FRIDAY...DISTURBANCE ROTATES AROUND THE UPPER LOW OVER NEVADA AND
WILL MOVE INTO THE REGION FROM THE SOUTHWEST. HIGH PRESSURE OVER
THE NORTHERN HIGH PLAINS WILL MAINTAIN UPSLOPE FLOW OVER THE
REGION. CONCEPTUALLY...THIS PATTERN CAN LEAD TO SEVERE CONVECTIVE
WEATHER ON THE PLAINS. MAIN CHALLENGE WILL BE THE AMOUNT OF
INSTABILITY AND LOW LEVEL MOISTURE. NAM HAS MORE COLD AIR OVER THE
REGION...WITH THE ATMOSPHERE REMAINING STABLE. THE GFS HAS THE
UPSLOPE FURTHER NORTH...AND BUFKIT SOUNDINGS SHOW THE LOW LEVEL
MOISTURE MIXING OUT OVER MUCH OF THE PLAINS...ESPECIALLY SOUTH OF
HIGHWAY 50. SUSPECT THE AMOUNT OF LOW LEVEL MOISTURE WILL BE A
COMPROMISE BETWEEN THE GFS AND NAM. THERE IS THE POTENTIAL FOR A
REGION OF HIGHER CAPE NEAR THE FRONT OVER THE EASTERN PLAINS.
CURRENTLY SPC DAY 3 OUTLOOK HAS SEVERE CONVECTION STAYING EAST OF
COLORADO. THIS IS A GOOD CALL GIVEN THE CURRENT MODEL OUTPUT WHICH
TENDS TO KEEP THE ATMOSPHERE STABLE.
.SATURDAY AND SUNDAY...UPPER LOW MOVES ACROSS COLORADO.
INTERESTING FORECAST FOR BOTH DAYS. ON SATURDAY...THERE WILL BE
NO SHORTAGE OF SHEAR AVAILABLE FOR SEVERE CONVECTIVE WEATHER. NAM
IS FURTHEST SOUTH OF THE UPPER LOW AND IT HAS THE MOST IMPRESSIVE
SHEAR. MAIN CHALLENGE WITH NAM SOLUTION WILL BE THE AMOUNT OF
INSTABILITY AS MODEL SOUNDINGS SHOW A GENERALLY STABLE ATMOSPHERE.
GFS AND EC TEND TO BE FURTHER NORTH...AND ARE PREFERRED. THESE
SOLUTIONS WOULD TEND TO MIX OUT THE LOW LEVEL MOISTURE OVER MUCH
OF THE PLAINS...ESPECIALLY SOUTH OF HIGHWAY 50. CURRENT THINKING
IS THE BEST CHANCES FOR STRONG TO SEVERE CONVECTION WILL BE IN
KIOWA AND EL PASO COUNTIES...BUT WILL HAVE TO WATCH FOR FURTHER
SOUTH SOLUTION. ON SUNDAY AS THE UPPER LOW LIFTS TO THE
NORTHEAST...UNSEASONABLY COLD AIR WILL MOVE SOUTHWARD INTO THE
REGION. EC AND GFS STILL HINT AT THE TROWAL MAKING INTO EL PASO
AND TELLER COUNTIES. IF THE TROWAL REACHES THIS FAR SOUTH...THEN A
PERIOD OF SNOW WITH GUSTY NORTH WINDS WILL OCCUR. LATER IN THE
DAY...THE GFS...AND TO A LESSER EXTENT...THE EC HAVE A SECONDARY
DISTURBANCE MOVING IN FROM THE NORTHWEST. BOTH MODELS HAVE
NORTHEAST UPSLOPE DEVELOP ALONG THE EASTERN MOUNTAINS WITH A
PERIOD OF SNOW...AS SNOW LEVELS AS LOW AS 6000 FEET. GIVEN THIS IS
STILL ON DAY 4...DID NOT HIT THIS SOLUTION HARD IN THE GRIDS.
.MONDAY THROUGH WEDNESDAY...AS THE UPPER LOW MOVES TO THE
NORTHEAST...A SHORTWAVE RIDGE BUILDS INTO THE REGION ON MONDAY. EC
AND GFS HINT AT ANOTHER DISTURBANCE MOVING INTO THE REGION ON
TUESDAY OR WEDNESDAY. MODELS CURRENTLY SUGGEST THE BEST LOW LEVEL
MOISTURE WILL MOVE EAST OF THE REGION...WITH CONVECTION NOT BEING
VERY STRONG. . --PGW--
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 345 PM MDT WED MAY 6 2015
WILL CONTINUE TO CARRY A VCTS MENTION AT ALL TAF SITES
INTO EARLY EVENING...WITH BEST CHANCE FOR TSRA SHIFTING SOUTH FROM
KCOS TOWARD KPUB 22Z-01Z. TSRA WILL THEN SHIFT EAST TOWARD THE KS
BORDER 01Z-03Z THIS EVENING...THOUGH SOME -SHRA MAY LINGER OVER THE
MOUNTAINS AND ACROSS EL PASO COUNTY 03Z-07Z. MAY SEE SOME PATCHY
GROUND FOG AT KALS ONCE AGAIN AFTER 10Z THU MORNING...THOUGH WON`T
INCLUDE IN TAF AT THIS POINT AS MID/HIGH LEVEL CLOUD DECK MAY HINDER
FORMATION. ON THURSDAY...VFR IN THE MORNING WITH SCATTERED AFTERNOON
TSRA ONCE AGAIN WITH BEST CHANCE AT KCOS AFTER 18Z.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MW
SHORT TERM...PETERSEN
LONG TERM...PGW
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
632 PM MDT WED MAY 6 2015
.SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT)
ISSUED AT 309 PM MDT WED MAY 6 2015
THE STRONG LOW THAT MOVED OVER THE AREA LAST NIGHT AND THIS
MORNING WILL CONTINUE MOVING INTO THE HIGH PLAINS TONIGHT.
NW AND CENTRAL CO AND NE UT WILL BE BENEATH THE NW FLOW ALOFT
ON THE WEST SIDE OF THE STORM...WHERE UNSTABLE AND MOIST
CONDITIONS WILL CONTINUE TO PRODUCE RAIN SHOWERS AND THUNDERSTORMS
OVER MUCH OF THE AREA. A FEW STORMS HAVE BEEN STRONG ENOUGH TO
PRODUCE SMALL HAIL AND HEAVY RAIN. A WEAK SHORTWAVE TROUGH MOVING
OVER NORTHWEST CO AND NE UT WILL ALSO AS SOME SUPPORT FOR
CONVECTION UNTIL ABOUT 03Z THIS EVENING. SUBSIDENCE AND GRADUALLY
DRIER AIR WILL FILTER INTO EASTER UT...AND NORTHWEST AND CENTRAL
CO AFTER MIDNIGHT. OVER SW CO...THE HRRR AND NAM12 SHOW ANOTHER
WEAK SHORTWAVE WILL BRING INCREASING CLOUDS AND ISOLATED
PRECIPITATION LATE TONIGHT.
THURSDAY MORNING...IN SOUTH FLOW A WEAK WAVE WORKS THROUGH THE
FOUR CORNERS REGION. AVAILABLE MOISTURE WILL BE DIMINISHING THERE
SO ONLY ISOLATED SHOWERS ARE FORECASTED ACROSS THE SOUTH FAVORING
THE SAN JUANS. DEEPER MOISTURE REMAINS ACROSS THE NORTH THURSDAY
ALONG WITH SOME WEAK FRONTAL FORCING. MARGINAL AFTERNOON
INSTABILITY WILL LIMIT THUNDERSTORM COVERAGE MAINLY OVER MTNS
NORTH OF I-70.
THURSDAY NIGHT DRIER SW FLOW INVADES LIMITING NIGHTTIME SHOWERS
TO NEAR THE CONTINENTAL DIVIDE. TEMPERATURES REMAIN NEAR NORMAL.
THE NEXT STRONGER PACIFIC LOW SINKS THROUGH CALIFORNIA ON THURSDAY
THEN BEGINS TO AMBLE INLAND THURSDAY NIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 309 PM MDT WED MAY 6 2015
A HIGHLY AMPLIFIED PROGRESSIVE PATTERN CONTINUES THROUGH THESE
PERIODS. ONE STRONG UPPER LOW WILL PASS ON SATURDAY BRINGING A
BLAST OF NORTHERN AND MOUNTAIN SNOW. TWO OTHER TROUGHS CURRENTLY
ARE TIMED TO PASS MID TO LATE NEXT WEEK.
FRIDAY THE UPPER LOW WITH A MODIFYING BUT IMPRESSIVE -26C COLD
CORE WORKS NORTH OF LAS VEGAS TO SOUTHCENTRAL UTAH FRIDAY NIGHT
AND THROUGH THE FORECAST AREA ON SATURDAY. THE THERMAL RIDGE
BLOSSOMS OVER THE FORECAST AREA FRIDAY AND HAVE RAISED
TEMPERATURES CLOSER TO THE WARMER NAM GUIDANCE. A 70KT JET NOSE
POKES INTO SE UTAH IN THE AFTERNOON AND RAKES THE SOUTH OVERNIGHT.
COOL ADVECTION ALOFT BEGINS TO DESTABILIZE BUT AVAILABLE MOISTURE
IS LIMITED AND MAINLY ACROSS THE NORTH.
SATURDAY THE POTENTIAL VORTICITY CENTER RAKES THE NORTH AS THE
JET WRAPS UP THE FRONT RANGE. FRONTAL FORCING SEEN IN THE PARK
RANGE BY THE AFTERNOON. THE BEST SHOWER COVERAGE WILL BE OVER THE
NORTHERN MOUNTAINS BUT WILL EXTEND INTO THE CENTRAL CO MTNS. SNOW
LEVELS DROP TO AROUND 8KFT...AND WILL BRIEFLY BE LOWER IN
STRONGER CONVECTION. THE LOW LIFTS THROUGH THE NORTHERN PLAINS
SATURDAY NIGHT THROUGH SUNDAY. WRAP- AROUND MOISTURE WILL CONTINUE
TO PRODUCE SHOWERS FAVORING THE NORTH. SUNDAY...SNOW LEVELS LOWER
INTO THE NORTHERN VALLEYS WITH 700MB TEMPS AT -4C THERE.
SIGNIFICANT SNOWFALL IS EXPECTED FOR THIS WEEKEND FOR THE EASTERN
UINTAS AND THE COLORADO MOUNTAINS FROM WYOMING DOWN INTO THE NW
SAN JUANS. TRAVEL THROUGH THESE MOUNTAINS COULD BE HAZARDOUS THIS
WEEKEND. COLDER THAN NORMAL TEMPERATURES EXPECTED ACROSS THE
REGION THROUGH SUNDAY NIGHT. HIGH VALLEY FREEZES ARE POSSIBLE.
MONDAY WARM ADVECTION BEGINS AS A RIDGE BUILDS IN FROM THE WEST.
FLOW ALOFT QUICKLY SWITCHES BACK TO SW AND INCREASES INTO THE NEW
WEEK AS THE NEXT TROUGH WORKS INTO THE PACIFIC NW ON TUESDAY AND
THE GREAT BASIN ON WEDNESDAY. AN ASSOCIATED ZONAL JET FROM CENTRAL
CALIFORNIA INTRUDES INTO THE NORTHERN-CENTRAL FORECAST AREA ON
WEDNESDAY BEGINNING THE CHANCE OF MAINLY RAIN SHOWERS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY AFTERNOON)
ISSUED AT 445 PM MDT WED MAY 6 2015
SCATTERED SHOWERS AND THUNDERSTORMS BY SUNSET WILL BECOME LIMITED
TO THE MOUNTAINS IN THE VICINITY OF THE CONTINENTAL DIVIDE AND
ALONG THE WYOMING BORDER. TAF SITES KEGE KASE MAY SEE BRIEF MVFR
CIGS IN -TSRA UNTIL 03Z. SHOWERS BECOME MORE ISOLATED IN COVERAGE
AFT 06Z. AFT 09Z SCT -SHRA ISOLATED -TSRA WILL DEVELOP OVER SW
COLORADO. TAF SITES KDRO KTEX MAY SEE BRIEF MVFR CIGS IN -SHRA.
AFT 15Z SCT MAINLY MTN -TSRA EXPECTED MAINLY NORTH OF HIGHWAY 50
CORRIDOR. TAF SITES KASE KEGE MAY SEE BRIEF MVFR CIGS IN
-TSRA/-SHRA.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...CC/JOE
LONG TERM...JOE
AVIATION...JOE
AREA FORECAST DISCUSSION
NWS PUEBLO CO
334 PM MDT TUE MAY 5 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 328 PM MDT TUE MAY 5 2015
CURRENTLY...UPPER LOW LIFTING SLOWLY E-NE ALONG THE CO/NM
BORDER...WITH DEEP E-SE FLOW DRIVING WIDESPREAD SHOWER ACTIVITY
ACROSS THE AREA. LACK OF INSTABILITY HAS KEPT THUNDERSTORMS TO A
MINIMUM...THOUGH A FEW LIGHTNING STRIKES HAVE BEGIN TO APPEAR ACROSS
THE SAN LUIS VALLEY AS STRONGER CONVECTION ROTATES NORTHWARD OUT OF
NEW MEXICO. RAINFALL RATES SO FAR TODAY HAVE BEEN FAIRLY
MODEST...WITH 0.25-0.50 INCH PER HOUR UNDER THE HEAVIEST
SHOWERS...MAINLY A TENTH OF INCH PER HOUR OR LESS UNDER THE LIGHTER
ACTIVITY.
TONIGHT...LATEST HRRR SUGGESTS BAND OF MODERATE TO HEAVY SHOWERS
ALONG THE ARKANSAS RIVER AT 21Z WILL LIKELY BE THE LAST AREA OF
ORGANIZED HEAVIER PRECIP THIS EVENING...WITH ACTIVITY LIFTING SLOWLY
NORTHWARD AND WEAKENING AFTER 00Z. STILL A LOW THREAT OF AN ISOLATED
TSRA THIS EVENING...ESPECIALLY SOUTHERN SECTIONS NEAR THE NM BORDER
WHERE INSTABILITY (CAPES 200-400 J/KG) IS SLIGHTLY DEEPER...BUT
OVERALL...CHANCE OF STRONGER CONVECTION AND EXTREME RAINFALL RATES
APPEARS TO BE FAIRLY LOW...SO WILL LET FLASH FLOOD WATCH END
SLIGHTLY EARLY WITH AFTERNOON FORECAST UPDATE. AS LOW LIFTS
NORTHEAST ACROSS THE AREA OVERNIGHT...SCATTERED SHOWERS WILL
CONTINUE OVER THE MOUNTAINS...WHILE DEVELOPING WESTERLY LOW/MID
LEVEL FLOW GRADUALLY BRINGS AN END TO PRECIP OVER THE I-25
CORRIDOR AND EASTERN PLAINS AFTER 06Z. WON`T MENTION FOG IN THE
FORECAST AS CLOUDS AND WEAK WESTERLY FLOW SHOULD KEEP VISIBILITY
FROM DROPPING TOO MUCH...THOUGH WITH PLENTIFUL RAIN/BL MOISTURE
AREAS OF GROUND FOG LOOK POSSIBLE...ESPECIALLY EL PASO COUNTY
WHERE LOW LEVEL FLOW TAKES MUCH OF THE NIGHT TO TURN W-NW.
WEDNESDAY...UPPER LOW LIFTS SLOWLY NORTHEAST INTO THE CENTRAL PLAINS
BY LATE AFTERNOON WITH LOW AND MID LEVEL FLOW BECOMING MORE SWLY
THROUGH THE DAY. MOISTURE DECREASES SOMEWHAT AS WELL...THOUGH WITH
RATHER STEEP LAPSE RATES DEVELOPING DURING THE AFTERNOON AND WEAK
UPPER WAVE LIFTING OUT OF THE SOUTHWEST...AT LEAST SCATTERED
AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS WILL DEVELOP MANY AREAS.
BEST CHANCES WILL BE ALONG THE CONTINENTAL DIVIDE AND NORTHERN
AREAS...LESSER POPS FARTHER SOUTH AND SOUTHEAST WHERE DRIER AIR
PUNCHES NORTHWARD FROM NM. MAX TEMPS WILL RECOVER ALL AREAS WITH
MORE SUN AND LACK OF WIDESPREAD RAINFALL...AND A FEW SPOTS ON THE
PLAINS WILL APPROACH 80F...WITH 60S AND 70S ACROSS MOST LOWER
ELEVATIONS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 328 PM MDT TUE MAY 5 2015
...WEATHER PATTERN TO REMAIN ACTIVE FOR NEXT SEVERAL DAYS...
AFTER A BRIEF LULL WEDNESDAY...WEDNESDAY NIGHT THROUGH
THURSDAY...LOW LEVEL UPSLOPE FLOW WILL REDEVELOP OVER THE
EASTERN PLAINS...LEADING TO MORE SHOWER AND THUNDERSTORM
CHANCES THURSDAY AFTERNOON AND EVENING...MAINLY FOR AREAS
ALONG AND NEAR THE EASTERN MOUNTAINS ACROSS THE PIKES
PEAK REGION...BUT ALSO FOR SPOTS OUT ON THE PLAINS. LOW LEVEL
EASTERLY FLOW COMBINED WITH UPPER LEVEL SOUTHWEST FLOW WILL INCREASE
SHEAR VALUES SUCH THAT A FEW SEVERE STORMS WILL BE POSSIBLE THURSDAY.
THURSDAY NIGHT THROUGH FRIDAY...LOW LEVEL UPSLOPE BECOMES MORE
FIRMLY ENTRENCHED ACROSS THE PLAINS. THE UPSLOPE LOOKS LIKE
IT GETS DEEP ENOUGH TO BRING IN WIDESPREAD LOW CLOUDS AND AREAS
OF LIGHT PRECIP...BUT POTENTIALLY REDUCES THE CONVECTIVE POTENTIAL
THIS DAY...BY LIMITING THE AMOUNT OF HEATING. SEVERE STORMS
PRESENTLY LOOK LESS LIKELY THIS DAY...BUT THIS IS CONTINGENT ON
HOW DEEP THE UPSLOPE FLOW REALLY TURNS OUT TO BE. COULD STILL HAVE
SOME PROBLEMS ALONG AND NEAR THE EAST SLOPES OF THE MOUNTAINS ACROSS
THE PIKES PEAK REGION...ESPECIALLY LATE FRIDAY AFTERNOON AND EVENING.
THEN...ON SATURDAY...WE BRING THE NEXT MAJOR NEGATIVE TILT TROUGH
NORTHEAST INTO SOUTHERN COLORADO. THIS TROUGH LOOKS VIGOROUS...WITH
THE POTENTIAL TO CREATE A LOT OF LIFT...AND GENERATE A LOT OF INTENSE
CONVECTION...IN A STRONGLY SHEARED ATMOSPHERE. PROBLEM IS...NOT
EXACTLY SURE WHAT TRAJECTORY THIS THING IS GOING TO TAKE AS IT
EJECTS NORTHEAST ON SATURDAY. THE 12Z GFS AND THE OLD 00Z ECMWF
TRACK IT FARTHER NORTH THAN SOME OF THE 06Z RUNS...GENERALLY
YIELDING LESS SEVERE POTENTIAL. BUT...IF THE 06Z RUNS TURN OUT
TO BE MORE TRUE TO FORM...WATCH OUT. COULD BE BIG SEVERE WEATHER
DAY OVER THE EAST...WITH TORNADO POTENTIAL AS WELL AS HAIL/WIND
POTENTIAL.
THEN...AS WE MOVE INTO SUNDAY...THINGS SHIFT OVER MORE TOWARD WINTER
WEATHER AS WE GET ON THE BACK SIDE OF THE SATURDAY SYSTEM. COLD AIR
ON THE BACK SIDE OF THE SYSTEM COULD BRING SNOW TO THE MOUNTAINS...
AND POSSIBLY DOWN TO THE LEVEL OF EL PASO COUNTY. FARTHER EAST...
AWAY FROM THE MOUNTAINS...IT WOULD LIKELY BE JUST SPOTTY LIGHTER
AMOUNTS OF RAIN.
NORTHWEST FLOW COULD BRING MORE RAIN AND SNOW SHOWERS TO THE
MOUNTAINS ON MONDAY. AND THEN...BY TUESDAY...IT`S LOOKING LIKE
ANOTHER ROUND OF MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS OVER
THE MOUNTAINS.
A LOT OF WEATHER TO TAKE PLACE OVER THE NEXT 7 DAYS. DETAILS
PRESENTED NOW WILL INEVITABLY CHANGE. PLEASE KEEP CHECKING BACK FOR
LATER UPDATES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 328 PM MDT TUE MAY 5 2015
AT KALS...PERIODS OF SHOWERS EXPECTED INTO EARLY EARLY
EVENING...WITH AN ISOLATED TSRA ALSO POSSIBLE. IN BETWEEN
SHOWERS...PREVAILING CONDITIONS WILL BE MAINLY VFR...WHILE UNDER THE
HEAVIER PRECIP MVFR CIGS/VIS ARE LIKELY. PRECIP DIMINISHES LATE THIS
EVENING AND OVERNIGHT...THOUGH MID-LEVEL CLOUD DECK WILL BE SLOW TO
CLEAR. ON WED...VFR WITH SCT -SHRA AND ISOLD -TSRA AFTER 18Z.
AT KCOS...RAIN SHOWERS WILL CONTINUE INTO THE EVENING WITH MAINLY
MVFR CONDITIONS...THOUGH SOME BRIEF IFR IS POSSIBLE UNDER THE HEAVIER
SHOWERS. LATE THIS EVENING AND OVERNIGHT SHOWERS WILL GRADUALLY
DIMINISH...THOUGH CIGS WILL BE SLOW TO LIFT WITH MVFR AND AREAS OF
IFR LIKELY TO PERSIST THROUGH THE NIGHT. MAY ALSO HAVE TO DEAL WITH
AT LEAST PATCHY AREAS OF FOG AS WELL WITH VERY WET GROUND AND MOIST
BOUNDARY LAYER. ON WED...ANY LOW CLOUDS SHOULD BREAK BY MID MORNING
WITH VFR CONDITIONS THROUGH THE DAY...THOUGH THERE WILL BE A CHANCE
OF TSRA AFTER 20Z.
AT KPUB...EXPECT PERIODS OF SHOWERS TO PERSIST INTO THE EVENING WITH
MVFR CONDITIONS UNDER THE HEAVIER PRECIP AND BRIEF VFR IN BETWEEN
SHOWERS. LATE THIS EVENING AND OVERNIGHT PRECIP WILL
DIMINISH...THOUGH AREAS OF MVFR CIGS WILL PERSIST ALONG WITH PATCHY
GROUND FOG AS WELL. ON WED...VFR FROM MID MORNING ONWARD WITH SCT -
SHRA AND ISOLD -TSRA AFTER 20Z.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...PETERSEN
LONG TERM...LW
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1042 AM EDT TUE MAY 5 2015
.SYNOPSIS...
A WEAK COLD FRONT MAY BRING A FEW BRIEF SHOWERS TODAY...BUT DRY
WEATHER AND MILD TEMPERATURES WILL DOMINATE. LITTLE CHANGE IS
EXPECTED THROUGH THE WEEKEND...WITH MILD TO WARM AFTERNOON/S AND
MAINLY DRY WEATHER PERSIST. A SLOW MOVING FRONT MAY BRING A FEW
SHOWERS LATE THIS WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1041 AM UPDATE...
WEAK COLD FRONT STILL CROSSING THE REGION. THIS FRONT EXTENDED
FROM JUST EAST OF KLWM...TO NEAR KORH...TO JUST SOUTH OF KBDL.
05/12Z CHH SOUNDING SHOWED AN IMPRESSIVE SURFACE-BASED INVERSION.
KBOX 88D SHOWING THE MAJORITY OF THE SHOWERS MOVING OVER THE
COASTAL WATERS EAST OF MA MID-MORNING. LATEST RUNS OF THE HRRR AND
RAP PREDICTING MORE SHOWERS DEVELOPING FARTHER WEST LATE THIS
MORNING...THEN MOVING ACROSS PORTIONS OF RI AND SOUTHEAST MA. THIS
IS ALSO STARTING TO SHOW IN THE RADAR DATA...SO RELIED HEAVILY ON
A HRRR/RAP COMBINATION TO UPDATE RAINFALL CHANCES THROUGH THE REST
OF TODAY.
TEMPERATURES WILL BE TRICKY. LOTS OF CLOUD COVER THIS MORNING.
VISIBLE SATELLITE DATA SHOWING PLENTY OF CLEARING THOUGH BEHIND
THE COLD FRONT...AT LEAST FOR NOW. OPEN-CELLULAR STRATOCUMULUS
CLOUDS STARTING TO POP ACROSS SOUTHERN VT AND SOUTHERN NH. FULLY
EXPECT THIS TREND TO CONTINUE ACROSS SOUTHERN NEW ENGLAND LATER
TODAY...ONCE THIS COLD FRONT MOVES COMPLETELY OFFSHORE. KEPT
TEMPERATURES WELL ABOVE NORMAL...BUT NOT QUITE AS HIGH AS
YESTERDAY.
PREVIOUS DISCUSSION...
PLENTY OF MID LEVEL CLOUDINESS WILL BE AROUND DURING THE MORNING...
BUT STILL EXPECT PEEKS OF SUN. AS THE AFTERNOON WEARS ON...EXPECT
SUNSHINE TO BECOME MORE PREVALENT AS DRIER AIR WORKS IN BEHIND THE
COLD FRONT.
GIVEN VERY MILD START...HIGH TEMPS IN MOST LOCALES SHOULD CLIMB WELL
UP INTO THE 70S. IT/S NOT OUT OF THE QUESTION THAT A SPOT
LOCATION OR TWO HITS 80. HOWEVER...ACROSS THE IMMEDIATE COAST
WEAKENING PRESSURE GRADIENT BEHIND THE COLD FRONT WILL ALLOW
COOLING SEA BREEZES TO DEVELOP. IN THESE LOCATIONS...MILD LATE
MORNING TEMPS WILL PROBABLY FALL BACK INTO THE UPPER 50S AND LOWER
60S...INCLUDING BOSTON. JUST INLAND FROM THE COAST THOUGH IT WILL
REMAIN QUITE MILD EVEN BEHIND THE FRONT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
TONIGHT AND WEDNESDAY...
DRY AND PLEASANT WEATHER EXPECTED FOR MOST OF TONIGHT AS HIGH
PRESSURE BUILDS IN BEHIND THE COLD FRONT. LOW TEMPS WILL MAINLY BE
IN THE 40S...TO LOWER 50S.
A MOISTURE STARVED SHORTWAVE WILL DROP DOWN IN WEST TO NORTHWEST
FLOW ALOFT WED MORNING. NOT SURE IF IT WILL TRACK FAR ENOUGH
NORTHWEST TO RESULT IN A BRIEF PERIOD OF SCATTERED SHOWERS ACROSS
ANY PORTION OF OUR REGION. BEST SHOT IS NORTHERN CT...AND PERHAPS
EVEN INTO PART OF RHODE ISLAND AND SOUTHEAST MA FOR A SHORT TIME.
REGARDLESS...EVEN IF A FEW SHOWERS OCCUR THEY WILL BE SHORT-LIVED
AND NOT AMOUNT TO MUCH. MORE IN THE WAY OF SUNSHINE SHOULD DEVELOP
FROM NORTH TO SOUTH THROUGH WED AFTERNOON. HIGHS SHOULD GENERALLY
REACH WELL INTO THE 70S IN MOST LOCATIONS...WITH THE WARMEST
READINGS NORTH OF THE PIKE WHERE THE MOST SUNSHINE IS EXPECTED. ITS
ALSO POSSIBLE THAT AREAS NEAR THE SOUTH COAST DO NOT REACH 70 ON
WEDNESDAY...IF CLOUDS HANG ON LONGER THEN EXPECTED.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
HIGHLIGHTS...
* SPRING TO SUMMER-LIKE TEMPERATURES THROUGH EARLY NEXT WEEK
* HIGH PRESSURE WILL KEEP MAINLY DRY CONDITIONS INTO THIS WEEKEND
* A SLOW MOVING FRONT MAY BRING SCATTERED SHOWERS SUN INTO MON
OVERVIEW AND MODEL PREFERENCES...
00Z GEFS/12Z ECENS REMAIN IN GOOD AGREEMENT WITH OVERALL UPPER
LEVEL STEERING FLOW IN KEEPING AMPLIFIED PATTERN ACROSS THE LOWER
48 THROUGH MOST OF THIS FORECAST PERIOD. NOTING LONG WAVE
TROUGHING WITH A FEW CUTOFF SHORT WAVES DIVE S INTO THE BASE OF
THE TROUGH INTO THIS WEEKEND WHILE LONG WAVE RIDGE SLOWLY BUILDS E
AS IT NOSES N THROUGH EASTERN QUEBEC TO LABRADOR. ALSO NOTING
NEARLY STATIONARY CUTOFF LOW OFF THE SE U.S. COAST WITH SURFACE
LOW/POSSIBLE SUBTROPICAL SYSTEM LATE IN THE WEEK OR THIS WEEKEND.
WHILE THIS SYSTEM WILL NOT DIRECTLY AFFECT THE REGION... IT COULD
CAUSE THE RIDGE TO HOLD IN PLACE AND SLOW AN APPROACHING COLD
FRONT FOR LATE THIS WEEKEND INTO NEXT MONDAY.
00Z MODEL SUITE ALSO IN FAIRLY GOOD AGREEMENT INTO THIS WEEKEND...
THEN THE GFS LOOKS TO BREAK DOWN RIDGING FASTER THAN GGEM/ECMWF...
MAINLY DUE TO SHORT WAVE TRYING TO WORK OUT OF CENTRAL CANADA
WHICH FLATTENS OUT THE RIDGE. WITH OVERALL BLOCKING PATTERN IN
PLACE ACROSS NORTH AMERICA AND FURTHER E ACROSS THE ATLC...FEEL
THIS WILL BE SLOW TO BREAK DOWN SO THINK THE SLOWER GUIDANCE IS
THE WAY TO GO FOR SUN-MON. HOWEVER...WITH THE WIDE MODEL
SOLUTIONS...HAVE LOW CONFIDENCE FROM SATURDAY INTO EARLY NEXT
WEEK.
LEANED TOWARD A BLEND OF MODEL GUIDANCE INTO THIS WEEKEND...THEN
BLENDED TOWARD THE ENSEMBLES FOR SUN-MON WHICH WAS CLOSE TO THE
HPC GUIDANCE. THIS YIELDED GOOD CONTINUITY TO THE PREVIOUS
FORECAST.
DETAILS...
WEDNESDAY NIGHT...EXPECT STALLED FRONT NEAR THE S COAST TO TEND TO
WASH OUT AS IT SHIFTS A BIT FURTHER S AS HIGH PRES AT THE SURFACE
AND ALOFT SLOWLY PUSHES ACROSS THE REGION. WILL SEE GENERALLY DRY
CONDITIONS WITH LIGHT/VRBL WINDS.
THURSDAY-FRIDAY...RIDGING BUILDS E ACROSS NEW ENGLAND INTO EASTERN
CANADA DURING THIS TIMEFRAME. EXPECT LIGHT/VRBL WINDS EARLY THU TO
BECOME S-SW. THIS WILL KEEP MILD TEMPS IN PLACE EXCEPT ALONG THE S
COAST WHERE THEY WILL BE TEMPERED WITH THE GENERAL ONSHORE WIND
FLOW. MAY ALSO SEE BRIEF SEA BREEZES ALONG THE E COAST MAINLY ON
FRIDAY. ALSO...DUE TO SEA SURFACE TEMPS RUNNING IN THE MID-UPPER
40S AND MILD TEMPS DURING THE NIGHTTIME HOURS...MAY SEE OVERNIGHT
PATCHY FOG DEVELOP MAINLY ALONG THE COAST WHILE INCREASING DEWPTS
MAY ALSO MEAN BRIEF PATCHY FOG ACROSS THE NORMALLY SUSCEPTIBLE
INLAND LOCATIONS EACH NIGHT.
HIGHS BOTH DAYS AWAY FROM THE S COAST WILL BE IN THE 70S...
POSSIBLY UP TO AROUND 80 ACROSS PORTIONS OF THE CT VALLEY BOTH
DAYS.
SATURDAY THROUGH MONDAY...AS MENTIONED ABOVE...MODEL SOLUTIONS
WIDEN. HAVE MENTIONED ONLY SLIGHT CHANCE POPS MAINLY N OF THE MASS
PIKE SAT AFTERNOON/NIGHT. INCREASED POPS TO ONLY LOW CHANCE FOR
SUN/MON FOR MOST AREAS...BUT WILL DEPEND UPON TIMING OF THE
APPROACHING FRONT. EXPECT MILD TEMPS TO REMAIN IN PLACE THROUGH
THIS WEEKEND WITH HIGHS IN THE 70S /EXCEPT COOLER ALONG IMMEDIATE
S COAST/.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /TODAY THROUGH WEDNESDAY/...
TODAY...HIGH CONFIDENCE. EXPECT VFR CONDITIONS...THOUGH CIGS WILL
LOWER TO 4-5KFT ALONG FRONT INVOF BAND OF SHOWERS AS IT MOVES S
OUT OF CENTRAL MA THROUGH MIDDAY. MAY SEE BRIEF LOCAL MVFR
CONDITIONS IN ANY HEAVIER SHOWERS.
TONIGHT AND WEDNESDAY...HIGH CONFIDENCE. MAINLY VFR CONDITIONS. A
BRIEF PERIOD OF ISOLATED TO SCATTERED SHOWERS MAY AFFECT NORTHERN CT
AND POSSIBLY A PART OF RI/SOUTHEAST MA FOR A TIME WED AM. THIS MAY
RESULT IN VERY BRIEF LOCALIZED MVFR CONDITIONS IF ANY OCCUR.
KBOS TAF...HIGH CONFIDENCE IN TAF. SEA BREEZES EXPECTED TO DEVELOP
THIS AFTERNOON AS A RESULT OF A WEAKENING PRESSURE GRADIENT BEHIND A
COLD FRONT.
KBDL TAF...HIGH CONFIDENCE IN TAF.
OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY...
HIGH CONFIDENCE THROUGH THE PERIOD. VFR AND DRY CONDITIONS. LOW
RISK FOR PATCHY FOG EACH NIGHT FROM AROUND MIDNIGHT THROUGH SUNRISE
WITH LOCAL MVFR-IFR CIGS/VSBYS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /TODAY THROUGH WEDNESDAY/...
TODAY THROUGH WEDNESDAY...HIGH CONFIDENCE. MARGINAL SMALL CRAFT
SEAS WILL CONTINUE TO DIMINISH ACROSS THE OUTER COASTAL WATERS
INTO THIS AFTERNOON. WINDS/SEAS WILL REMAIN BELOW SMALL CRAFT
ADVISORY THRESHOLDS THROUGH WEDNESDAY UNDER A WEAK RIDGE OF HIGH
PRESSURE.
OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY...HIGH CONFIDENCE
THROUGH THE PERIOD.
WEDNESDAY NIGHT...LIGHT/VRBL WINDS BECOME S-SW AROUND OR AFTER
MIDNIGHT AT 15 KT OR LESS. SEAS 3 FT OR LESS.
THURSDAY...W-SW WINDS UP TO 15 KT ACROSS THE OPEN WATERS DURING
THE AFTERNOON. SEAS REMAIN BELOW 5 FT.
THURSDAY NIGHT THROUGH SATURDAY...SW WINDS 15 KT OR LESS WITH SEAS
2-4 FT. LOW CHANCE OF 5 FT SEAS ON THE EASTERN OUTER WATERS SAT
AFTERNOON/NIGHT.
&&
.FIRE WEATHER...
MAINLY DRY WEATHER WITH LITTLE APPRECIABLE RAINFALL WILL CONTINUE
THROUGH AT LEAST SATURDAY IF NOT INTO SUNDAY/MONDAY. WHILE WINDS
FOR THE REST OF THE WORK WEEK WILL PROBABLY NOT BE STRONG ENOUGH
FOR FIRE WEATHER HEADLINES...WE MAY HAVE TO BE MORE CONCERNED BY
SATURDAY. THERE WILL BE AT LEAST A BIT MORE POTENTIAL FOR SOME
MARGINAL FIRE WEATHER HEADLINE WIND GUSTS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...FRANK/EVT
NEAR TERM...BELK/FRANK/EVT
SHORT TERM...FRANK
LONG TERM...EVT
AVIATION...BELK/FRANK/EVT
MARINE...BELK/FRANK/EVT
FIRE WEATHER...STAFF
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1020 PM EDT WED MAY 6 2015
.DISCUSSION...
...LOW PRESSURE CONTINUES TO DEVELOP OFFSHORE BRINGING ROUGH
SURF...HAZARDOUS BOATING CONDITIONS...MINOR BEACH EROSION...AND
A MODERATE RISK OF RIP CURRENTS...
...LAND IMPACTS OF THE LOW WANE AS THE CENTER CONSOLIDATES AND MOVES
NORTH TOWARD THE CAROLINAS...
UPDATE...WINDS BACKING FROM THE NORTH TO NORTHWEST AND WEST AFTER
MIDNIGHT WILL PUSH ANY SHOWERS ON THE NEARSHORE AND IMMEDIATE COAST
OFFSHORE.
ZONES UPDATE...THE DEVELOPING LOW PRESSURE AND UPPER LEVEL TROUGHING
EAST OF FLORIDA FORECAST TO CONTINUE TO SLOWLY LIFT NORTH NORTHEAST
OVERNIGHT. THIS WILL RELAX THE GRADIENT BETWEEN THE WEAK HIGH
PRESSURE OVER NORTH FLORIDA AND THE DEVELOPING LOW PRESSURE OVER THE
BAHAMA ISLANDS THE ATLANTIC EAST OF CENTRAL FLORIDA. WINDS WILL
CONTINUE TO BACK TO THE NORTH THROUGH WEST AS THE AREA OF LOW
PRESSURE LIFTS NORTH NORTHEAST. RADAR TRENDS SHOWING THAT
PRECIPITATION SHOULD END WEST TO EAST OVER MAINLAND EAST CENTRAL
FLORIDA THROUGH MIDNIGHT.
CURRENT ZONES FORECAST LOOKS GOOD HOWEVER...NEED TO REMOVE PRE FIRST
PERIOD WORDING.
.AVIATION...VFR.
.MARINE...BUOY 009 WAS RECORDING NORTH WINDS 12 TO 16 KNOTS. SEAS 7
FOOT AND HIGHER WELL OFFSHORE PAST FEW HOURS. SEAS SHOULD SUBSIDE TO
SEAS 6 FEET OR LESS WELL OFFSHORE LATE OVERNIGHT.
PREVIOUS DISCUSSION
CURRENT-TONIGHT...UPPER TROUGHING CONTINUES OFF OF THE EAST FLORIDA
COAST THIS AFTERNOON. A WEAK SURFACE LOW LOCATED NORTH OF THE
NORTHWEST BAHAMAS WILL CONTINUE TO MIGRATE SLOWLY NORTHWARD. SEA
BREEZE BOUNDARY MOVING INLAND THIS AFTERNOON WITH SCATTERED SHOWERS
AND ISOLATED THUNDER OCCURRING FROM NEAR LAKE GEORGE THROUGH THE I-4
CORRIDOR AND FURTHER SOUTHWARD. MOVEMENT OF THIS ACTIVITY IS PRETTY
MUCH NORTH TO SOUTH. FOR THE MOST PART WINDS AGAIN HAVE NOT BEEN AS
ADVERTISED OWING TO THE FACT STRONGER WINDS HAVE NOT BEEN ALLOWED TO
MIX DOWN TO THE SURFACE (LIMITED HEATING) WITH THE CLOUD COVER AND
PRECIPITATION AROUND. AT ANY RATE OUR N/NNE DIRECTIONAL COMPONENT IS
FORECAST TO BACK TO THE NW THIS EVENING/OVERNIGHT AS THE
AFOREMENTIONED LOW VENTURES FURTHER NORTH.
DEEP MOISTURE STILL FORECAST TO LIFT NORTHEAST OF THE AREA TONIGHT
AS DRIER AIR WRAPS AROUND THE PERIPHERY OF THE LOW PRESSURE SYSTEM.
WILL KEEP SOME LOW EVENING COASTAL SHOWER CHANCES THAT SHOULD END BY
MID/LATE EVENING ALTOGETHER...IF NOT SOONER. THIS THE RESULT OF
DRIER AIR MOVING IN FROM THE NORTHERN PENINSULA.
AT THE BEACHES ROUGH SURF...A MODERATE RISK FOR RIP CURRENTS
(STRONGEST) FROM MID TO LATE AFTERNOON...AND A LONG SHORE CURRENT
WITH MINOR BEACH EROSION EXPECTED. SKIES FORECAST TO THIN THIS
EVENING AND OVERNIGHT. LOWS COOLER WITH L/M 60S AREAWIDE FORECAST.
THU...LOW PRESSURE WELL OFFSHORE OF THE NORTHEAST FL COAST EARLY IN
THIS PERIOD WILL CONTINUE A SLOW N-NW MOVEMENT AWAY FROM ECFL. A
WEAKER PRESSURE GRADIENT WILL BE IN PLACE ON THIS DAY WITH NORTHWEST
WINDS FOR MUCH OF THE DAY BECOMING ONSHORE IN THE AFTERNOON ALONG
THE COAST. HAVE OPTED TO KEEP THE ENTIRE COVERAGE WARNING AREA DRY
FOR NOW...BUT FUTURE SHIFTS MAY HAVE TO MONITOR IF ENOUGH RESIDUAL
MOISTURE WILL BE AVAILABLE FOR SHOWERS NEAR LAKE OKEECHOBEE WITH ANY
ECSB/LAKE BREEZE CLASHES. A CRUNCHING OF THE NUMBERS FROM RECENT
MODEL RUNS SUGGEST AFTERNOON RELATIVE HUMIDITY VALUES WILL FALL INTO
THE 30S/40S INLAND FROM THE COAST. AFTERNOON HIGHS MUCH WARMER THAN
THE PREVIOUS COUPLE OF DAYS WITH L80S ALONG THE VOLUSIA/NORTH
BREVARD COASTS...M80S IN PLAY FURTHER SOUTHWARD ALONG THE COAST AND
U80S INTO THE INTERIOR.
THU NIGHT-SUN NIGHT...DECELERATING SFC LOW OFF THE SC COAST WILL
SLOW TO A CRAWL APPROACHING THE COAST AT/NEAR THE SC/NC BORDER AS
THE LOW-MID LEVEL RIDGE TO ITS NORTH BLOCKS ITS ESCAPE. WRN NOSE OF
THE ATLC RIDGE WILL TRY TO BUILD WWD INTO SOUTH FL BY LATE IN THE
WEEKEND. THERE REMAINS SOME DIFFS AS TO WHETHER ANY SIGNIFICANT
RETROGRADE OF THE CENTER TWD THE W OR WSW WILL OCCUR...WHICH WOULD
HAVE IMPLICATIONS ON WHETHER WRAP AROUND MOISTURE CAN MAKE IT ALL
THE WAY BACK DOWN INTO NRN SECTIONS OF ECFL BY THIS WEEKEND. IMPACT
OF ANY SHOWERS WOULD BE MINOR IN ANY EVENT. HAVE A SMALL POP FOR
VOLUSIA/NRN BREVARD ON SAT OWING TO THIS POSSIBILITY...THEN A SMALL
CHC FOR DIURNAL SHRA/TS ALL AREAS SUN. MAX TEMPS RECOVER TO ABOVE
NORMAL WHILE MINS NEAR TO BELOW NORMAL MINS THU-FRI NIGHTS MODIFY
OVER THE WEEKEND.
MON-WED (PREV)...THE ATLC RIDGE AXIS WILL REESTABLISH ITSELF OVER
THE FL STRAITS AND BUILD SLOWLY NWD AS THE CAROLINA LOW CREEPS UP
THE ERN SEABOARD. SRLY BREEZE WILL PREVAIL THRU THE H100-H70 LYR
INTO EARLY NEXT WEEK...A FLOW THAT WILL TAP A CARIBBEAN AIRMASS THAT
IS ON THE DRY SIDE. LATEST RAP ANALYSIS SHOWS H100-H70 RH VALUES
LARGELY AOB 70PCT...WHICH WILL IMPEDE MOISTURE LOADING ACRS THE
GOMEX/W ATLC REGION. WILL BRING PRECIP BACK INTO THE FCST ON
SUN...BUT LIMITING POPS TO 20-30PCT RANGE THRU THE FIRST PART OF
NEXT WEEK. SRLY FLOW WILL GENERATE ABV AVG TEMPS...AFTN MAXES IN THE
M/U80S...MRNG MINS IN THE U60S/L70S.
&&
.AVIATION...DEEPENING LOW PRESSURE NORTH OF THE BAHAMAS WILL
CONTINUE TO MOVE NORTHWARD TONIGHT. SCT SHRA/ISOLD TSRA ACTIVITY
WILL END OVER LAND THIS EVENING AS IT EVENTUALLY MOVES OFF INTO THE
WESTERN PENINSULA AND DISSIPATES WITH THE DIURNAL CYCLE. HAVE KEPT A
SMALL POP THIS EVENING ALONG THE COAST BUT SUSPECT MOST PLACES WILL
REMAIN DRY HERE. CURRENT N/NNE WINDS WILL VEER TO NW OVERNIGHT.
GENERALLY VFR CIGS WITH MVFR CIGS ASSOCIATED WITH SHOWERS/ISOLD
TSRA. LOW PRESSURE CONTINUES TO PULL NORTHWARD AWAY FROM THE AREA ON
THU. MAINLY NW WINDS WITH ONSHORE FLOW DEVELOPING IN THE AFTERNOON
ALONG THE EAST COAST.
&&
.MARINE...CURRENT-TONIGHT...DEEPENING LOW PRESSURE NORTH OF THE
BAHAMAS WILL CONTINUE A NORTH TRACK OVERNIGHT. CURRENT CONDITIONS
WARRANT BRINGING AN END TO THE SCA NEAR SHORE WITH NEXT CWA ISSUANCE
AT 4PM/20Z. WILL REPLACE WITH CAUTIONARY STATEMENTS THOUGH. OFFSHORE
SEAS REMAIN ELEVATED 6-9 FT. SEAS 4-6 FT NEAR SHORE. N/NNE WINDS
WILL VEER TO NW THIS EVENING AND OVERNIGHT. SHOWERS AND ISOLD STORMS
WILL BE ON A DECREASING TREND THIS EVENING AND OVERNIGHT.
THU...THE LOW PRESSURE CONTINUES TO MOVE N/NNW AWAY FROM THE COASTAL
WATERS. WINDS WILL BE ON A DOWNWARD TREND...REMAINING NWRLY...EXCEPT
BECOMING ONSHORE IN THE AFTERNOON ALONG THE COAST WITH SEA BREEZE
DEVELOPMENT. SEAS WILL CONTINUE TO BE ELEVATED WITH SWELLS GENERATED
FROM THE NEARBY LOW PRESSURE SYSTEM. SUSPECT AN SCA WILL STILL BE
NECESSARY OVER THE OPEN ATLC FOR THE SEAS WITH EXERCISE CAUTION
STILL NECESSARY NEAR SHORE.
THU NIGHT-FRI NIGHT...LIGHT TO GENTLE WRLY BREEZE TO START FRI. THE
WEAK SFC PGRAD WILL ALLOW SFC WINDS TO SHIFT TO THE E/SE BY AFTN AS
THE EAST COAST SEA BREEZE DVLPS. AS THE STORM MOVES OVER OR NEAR THE
COASTAL CAROLINAS...THE ATLC RIDGE WILL REBUILD WWD INTO THE FL
STRAITS/S FL PENINSULA AFT SUNSET...ALLOWING WINDS TO SHIFT TO THE
S/SW. SEAS SUBSIDING TO 2-3FT NEAR SHORE/4-5FT OFFSHORE WILL SUBSIDE
BY ABOUT A FOOT AS SWELL IS PROGGED TO GRADUALLY DECAY...WITH A
MINIMAL WIND CHOP.
SAT-MON...ATLC RIDGE WILL BUILD SLOWLY NWD THRU THE WEEKEND AS THE
CAROLINA LOW CREEPS UP THE COAST. SRLY BREEZE WILL PREVAIL...
SHIFTING BTWN SW AND SE WITH THE FORMATION OF DIURNAL SEA BREEZES.
SEAS GENERALLY 2FT NEAR SHORE/3FT OFFSHORE...BUILDING BY A FOOT OR
SO EARLY NEXT WEEK AS SRLY FLOW ON THE WRN SIDE OF THE ATLC STARTS
TO FRESHEN.
CAVEAT WITH THIS FCST WILL BE THAT SHOULD THE LOW DEEPEN AS A STC OR
SC MORE THAN CURRENTLY PROGGED...IT WOULD SEND SOME HIGHER SWELLS
DOWN AT US INTO THE WEEKEND.
&&
.FIRE WEATHER...THU...DRIER AIR WILL FILTER DOWN THE PENINSULA ON
THE BACKSIDE OF THE RECENT LOW PRESSURE WITH AFTERNOON LOW MIN RH
VALUES FORECAST TO FALL INTO THE 30S OVER THE INTERIOR FROM OSCEOLA
COUNTY NORTHWARD. DISPERSION INDICES WILL BE GENERALLY GOOD IN THE
AFTERNOON. NW 20 FT WINDS IN UPWARDS OF AROUND 10 MPH...EXCEPT ALONG
THE COAST WHERE AN ONSHORE (NNE/NE) COMPONENT DEVELOPS IN THE
AFTERNOON. MUCH WARMER WITH HIGHS IN THE U80S ACROSS THE INTERIOR.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 63 82 64 84 / 20 0 10 10
MCO 66 87 64 87 / 10 0 10 10
MLB 65 83 64 86 / 20 0 10 10
VRB 65 85 64 87 / 20 0 10 10
LEE 65 87 64 86 / 10 0 10 10
SFB 65 89 63 87 / 10 0 10 10
ORL 67 86 66 87 / 10 0 10 10
FPR 62 85 62 89 / 20 0 10 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THURSDAY FOR FLAGLER BEACH
TO VOLUSIA-BREVARD COUNTY LINE 20-60 NM-SEBASTIAN INLET TO
JUPITER INLET 20-60 NM-VOLUSIA-BREVARD COUNTY LINE TO
SEBASTIAN INLET 20-60 NM.
&&
$$
LONG TERM/IMPACT WX...PENDERGRAST
SHORT TERM/AVIATION...WIMMER
AREA FORECAST DISCUSSION
NWS MIAMI FL
900 PM EDT WED MAY 6 2015
.UPDATE...
SHOWERS AND THUNDERSTORMS ARE WEAKENING THROUGH
GLADES/HENDRY/COLLIER COUNTIES THIS EVENING. WILL KEEP SOME POPS
IN THESE COUNTIES AS THIS OCCURS, ALSO THE HRRR DOES KEEP SOME
ACTIVITY THERE OVERNIGHT, ALTHOUGH NOT MUCH IS EXPECTED.
INCREASING DRYING ALOFT AND WEAK WINDS SHOULD KEEP THE REST OF THE
REGION DRY OVERNIGHT.
&&
.PREV DISCUSSION... /ISSUED 721 PM EDT WED MAY 6 2015/
AVIATION...
SCATTERED SHOWERS AND A FEW THUNDERSTORMS HAVE DEVELOPED OVER THE
WESTERN INTERIOR AREAS THIS EVENING. THIS ACTIVITY SHOULD STAY
EAST OF KAPF TAF SITE. THEREFORE...ALL OF THE TAF SITES WILL
REMAIN DRY TONIGHT ALONG WITH VFR CONDITIONS IN THE CEILING AND
VIS. THE WINDS SHOULD BECOME LIGHT AND VARIABLE OR EVEN A LIGHT
DRAINAGE FLOW AFTER 02Z TONIGHT BEFORE BECOMING EASTERLY ON
THURSDAY AFTERNOON OVER THE EAST COAST TAF SITES AROUND 10 KNOTS.
FOR KAPF TAF SITE...THE WINDS SHOULD BECOME WESTERLY AFTER 15Z ON
FRIDAY WITH SPEEDS AROUND 10 KNOTS.
AVIATION...54/BNB
PREV DISCUSSION... /ISSUED 332 PM EDT WED MAY 6 2015/
SYNOPSIS...
LOW PRESSURE WILL MOVE NORTH AWAY FROM THE AREA THIS WEEK...WITH
HIGH PRESSURE BUILDING IN IN ITS WAKE. DIURNAL SHOWERS WILL BE
SCATTERED AND FOCUSED OVER THE INTERIOR.
SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
LOW PRESSURE NORTH OF THE BAHAMAS HAS ORGANIZED TODAY...AND NHC
NOW GIVES THIS FEATURE A 60 PERCENT CHANCE OF FORMATION BY FRIDAY.
REGARDLESS OF DEVELOPMENT...THE SYSTEM WILL CONTINUE MOVING
NORTHWARD...AWAY FROM SOUTH FLORIDA.
THIS AFTERNOON CONVECTION HAS BEEN SLOW TO FIRE AND THERE IS
UNCERTAINTY AS TO WHETHER OR NOT IT WILL DEVELOP AT ALL. CHANCE
POPS AREAWIDE THROUGH 0Z MAY NEED TO BE ADJUSTED DOWN IF CURRENT
TRENDS PREVAIL. BY LATE THIS EVENING...AND SHOWERS/STORMS WILL
HAVE DISSIPATED.
TEMPERATURES WILL EXHIBIT A GRADUALLY WARMING TREND FOR THE
REMAINDER OF THE WEEK...AS SUBTROPICAL RIDGE TAKES HOLD. RAIN
CHANCES WILL BE DIURNAL IN NATURE...WITH GREATEST COVERAGE OVER
THE INTERIOR...WHERE SEA-BREEZES WILL BE DURING MAXIMUM HEATING.
LONG TERM /SATURDAY THROUGH TUESDAY/...
THIS WEEKEND INTO NEXT WEEK...LITTLE CHANGE IN THE WEATHER
PATTERN. SUBTROPICAL RIDGING WILL DOMINATE...PROVIDING SOUTH
FLORIDA WITH SUMMER-LIKE WEATHER. ABOVE NORMAL TEMPERATURES AND
ISOLATED/SCATTERED SHOWERS ARE EXPECTED.
AVIATION...
IT IS STILL NOT CLEAR IF AN EAST COAST SEA BREEZE WILL DEVELOP
THIS AFTERNOON. MODELS ARE LESS EXCITED ABOUT THIS SCENARIO. THE
FLOW AROUND THE LOW PRESSURE SEEMS TO BE STRONG ENOUGH THAT THE
MOST LIKELY SCENARIO IS FOR THE GULF BREEZE TO INTERACT WITH THE
THE NORTHWESTERLY FLOW OVER THE INTERIOR TO GENERATE SHOWERS AND
POSSIBLY A THUNDERSTORM OR TWO. FOR NOW, HAVE INCLUDED VCTS ONLY
FOR PBI AND VCSH FOR ALL THE OTHER AIRPORTS EXCEPT FOR APF.
MARINE...
WINDS AND SEAS WILL CONTINUE TO SUBSIDE TONIGHT AND
THURSDAY. SWELL FROM THE LOW PRESSURE NORTH OF THE BAHAMAS MAY
IMPACT THE AREA IN A FEW DAYS DEPENDING ON HOW MUCH IT
STRENGTHENS. WINDS WILL BE FAIRLY LIGHT AND VARIABLE INTO THE
WEEKEND...AS HIGH PRESSURE SETTLES IN.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 68 84 69 88 / 10 20 10 30
FORT LAUDERDALE 71 86 72 88 / 10 20 10 30
MIAMI 70 87 72 88 / 10 20 10 40
NAPLES 68 86 69 87 / 20 10 10 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...21/KM
LONG TERM....21/KM
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
830 PM EDT WED MAY 6 2015
.DISCUSSION...
...LOW PRESSURE CONTINUES TO DEVELOP OFFSHORE BRINGING ROUGH
SURF...HAZARDOUS BOATING CONDITIONS...MINOR BEACH EROSION...AND
A MODERATE RISK OF RIP CURRENTS...
...LAND IMPACTS OF THE LOW WANE AS THE CENTER CONSOLIDATES AND MOVES
NORTH TOWARD THE CAROLINAS...
ZONES UPDATE...THE DEVELOPING LOW PRESSURE AND UPPER LEVEL TROUGHING
EAST OF FLORIDA FORECAST TO CONTINUE TO SLOWLY LIFT NORTH NORTHEAST
OVERNIGHT. THIS WILL RELAX THE GRADIENT BETWEEN THE WEAK HIGH
PRESSURE OVER NORTH FLORIDA AND THE DEVELOPING LOW PRESSURE OVER THE
BAHAMA ISLANDS THE ATLANTIC EAST OF CENTRAL FLORIDA. WINDS WILL
CONTINUE TO BACK TO THE NORTH THROUGH WEST AS THE AREA OF LOW
PRESSURE LIFTS NORTH NORTHEAST. RADAR TRENDS SHOWING THAT
PRECIPITATION SHOULD END WEST TO EAST OVER MAINLAND EAST CENTRAL
FLORIDA THROUGH MIDNIGHT.
CURRENT ZONES FORECAST LOOKS GOOD HOWEVER...NEED TO REMOVE PRE FIRST
PERIOD WORDING.
.AVIATION...VFR.
.MARINE...BUOY 009 WAS RECORDING NORTH WINDS 12 TO 16 KNOTS. SEAS 7
FOOT AND HIGHER WELL OFFSHORE PAST FEW HOURS. SEAS SHOULD SUBSIDE TO
SEAS 6 FEET OR LESS WELL OFFSHORE LATE OVERNIGHT.
PREVIOUS DISCUSSION
CURRENT-TONIGHT...UPPER TROUGHING CONTINUES OFF OF THE EAST FLORIDA
COAST THIS AFTERNOON. A WEAK SURFACE LOW LOCATED NORTH OF THE
NORTHWEST BAHAMAS WILL CONTINUE TO MIGRATE SLOWLY NORTHWARD. SEA
BREEZE BOUNDARY MOVING INLAND THIS AFTERNOON WITH SCATTERED SHOWERS
AND ISOLATED THUNDER OCCURRING FROM NEAR LAKE GEORGE THROUGH THE I-4
CORRIDOR AND FURTHER SOUTHWARD. MOVEMENT OF THIS ACTIVITY IS PRETTY
MUCH NORTH TO SOUTH. FOR THE MOST PART WINDS AGAIN HAVE NOT BEEN AS
ADVERTISED OWING TO THE FACT STRONGER WINDS HAVE NOT BEEN ALLOWED TO
MIX DOWN TO THE SURFACE (LIMITED HEATING) WITH THE CLOUD COVER AND
PRECIPITATION AROUND. AT ANY RATE OUR N/NNE DIRECTIONAL COMPONENT IS
FORECAST TO BACK TO THE NW THIS EVENING/OVERNIGHT AS THE
AFOREMENTIONED LOW VENTURES FURTHER NORTH.
DEEP MOISTURE STILL FORECAST TO LIFT NORTHEAST OF THE AREA TONIGHT
AS DRIER AIR WRAPS AROUND THE PERIPHERY OF THE LOW PRESSURE SYSTEM.
WILL KEEP SOME LOW EVENING COASTAL SHOWER CHANCES THAT SHOULD END BY
MID/LATE EVENING ALTOGETHER...IF NOT SOONER. THIS THE RESULT OF
DRIER AIR MOVING IN FROM THE NORTHERN PENINSULA.
AT THE BEACHES ROUGH SURF...A MODERATE RISK FOR RIP CURRENTS
(STRONGEST) FROM MID TO LATE AFTERNOON...AND A LONG SHORE CURRENT
WITH MINOR BEACH EROSION EXPECTED. SKIES FORECAST TO THIN THIS
EVENING AND OVERNIGHT. LOWS COOLER WITH L/M 60S AREAWIDE FORECAST.
THU...LOW PRESSURE WELL OFFSHORE OF THE NORTHEAST FL COAST EARLY IN
THIS PERIOD WILL CONTINUE A SLOW N-NW MOVEMENT AWAY FROM ECFL. A
WEAKER PRESSURE GRADIENT WILL BE IN PLACE ON THIS DAY WITH NORTHWEST
WINDS FOR MUCH OF THE DAY BECOMING ONSHORE IN THE AFTERNOON ALONG
THE COAST. HAVE OPTED TO KEEP THE ENTIRE COVERAGE WARNING AREA DRY
FOR NOW...BUT FUTURE SHIFTS MAY HAVE TO MONITOR IF ENOUGH RESIDUAL
MOISTURE WILL BE AVAILABLE FOR SHOWERS NEAR LAKE OKEECHOBEE WITH ANY
ECSB/LAKE BREEZE CLASHES. A CRUNCHING OF THE NUMBERS FROM RECENT
MODEL RUNS SUGGEST AFTERNOON RELATIVE HUMIDITY VALUES WILL FALL INTO
THE 30S/40S INLAND FROM THE COAST. AFTERNOON HIGHS MUCH WARMER THAN
THE PREVIOUS COUPLE OF DAYS WITH L80S ALONG THE VOLUSIA/NORTH
BREVARD COASTS...M80S IN PLAY FURTHER SOUTHWARD ALONG THE COAST AND
U80S INTO THE INTERIOR.
THU NIGHT-SUN NIGHT...DECELERATING SFC LOW OFF THE SC COAST WILL
SLOW TO A CRAWL APPROACHING THE COAST AT/NEAR THE SC/NC BORDER AS
THE LOW-MID LEVEL RIDGE TO ITS NORTH BLOCKS ITS ESCAPE. WRN NOSE OF
THE ATLC RIDGE WILL TRY TO BUILD WWD INTO SOUTH FL BY LATE IN THE
WEEKEND. THERE REMAINS SOME DIFFS AS TO WHETHER ANY SIGNIFICANT
RETROGRADE OF THE CENTER TWD THE W OR WSW WILL OCCUR...WHICH WOULD
HAVE IMPLICATIONS ON WHETHER WRAP AROUND MOISTURE CAN MAKE IT ALL
THE WAY BACK DOWN INTO NRN SECTIONS OF ECFL BY THIS WEEKEND. IMPACT
OF ANY SHOWERS WOULD BE MINOR IN ANY EVENT. HAVE A SMALL POP FOR
VOLUSIA/NRN BREVARD ON SAT OWING TO THIS POSSIBILITY...THEN A SMALL
CHC FOR DIURNAL SHRA/TS ALL AREAS SUN. MAX TEMPS RECOVER TO ABOVE
NORMAL WHILE MINS NEAR TO BELOW NORMAL MINS THU-FRI NIGHTS MODIFY
OVER THE WEEKEND.
MON-WED (PREV)...THE ATLC RIDGE AXIS WILL REESTABLISH ITSELF OVER
THE FL STRAITS AND BUILD SLOWLY NWD AS THE CAROLINA LOW CREEPS UP
THE ERN SEABOARD. SRLY BREEZE WILL PREVAIL THRU THE H100-H70 LYR
INTO EARLY NEXT WEEK...A FLOW THAT WILL TAP A CARIBBEAN AIRMASS THAT
IS ON THE DRY SIDE. LATEST RAP ANALYSIS SHOWS H100-H70 RH VALUES
LARGELY AOB 70PCT...WHICH WILL IMPEDE MOISTURE LOADING ACRS THE
GOMEX/W ATLC REGION. WILL BRING PRECIP BACK INTO THE FCST ON
SUN...BUT LIMITING POPS TO 20-30PCT RANGE THRU THE FIRST PART OF
NEXT WEEK. SRLY FLOW WILL GENERATE ABV AVG TEMPS...AFTN MAXES IN THE
M/U80S...MRNG MINS IN THE U60S/L70S.
&&
.AVIATION...DEEPENING LOW PRESSURE NORTH OF THE BAHAMAS WILL
CONTINUE TO MOVE NORTHWARD TONIGHT. SCT SHRA/ISOLD TSRA ACTIVITY
WILL END OVER LAND THIS EVENING AS IT EVENTUALLY MOVES OFF INTO THE
WESTERN PENINSULA AND DISSIPATES WITH THE DIURNAL CYCLE. HAVE KEPT A
SMALL POP THIS EVENING ALONG THE COAST BUT SUSPECT MOST PLACES WILL
REMAIN DRY HERE. CURRENT N/NNE WINDS WILL VEER TO NW OVERNIGHT.
GENERALLY VFR CIGS WITH MVFR CIGS ASSOCIATED WITH SHOWERS/ISOLD
TSRA. LOW PRESSURE CONTINUES TO PULL NORTHWARD AWAY FROM THE AREA ON
THU. MAINLY NW WINDS WITH ONSHORE FLOW DEVELOPING IN THE AFTERNOON
ALONG THE EAST COAST.
&&
.MARINE...CURRENT-TONIGHT...DEEPENING LOW PRESSURE NORTH OF THE
BAHAMAS WILL CONTINUE A NORTH TRACK OVERNIGHT. CURRENT CONDITIONS
WARRANT BRINGING AN END TO THE SCA NEAR SHORE WITH NEXT CWA ISSUANCE
AT 4PM/20Z. WILL REPLACE WITH CAUTIONARY STATEMENTS THOUGH. OFFSHORE
SEAS REMAIN ELEVATED 6-9 FT. SEAS 4-6 FT NEAR SHORE. N/NNE WINDS
WILL VEER TO NW THIS EVENING AND OVERNIGHT. SHOWERS AND ISOLD STORMS
WILL BE ON A DECREASING TREND THIS EVENING AND OVERNIGHT.
THU...THE LOW PRESSURE CONTINUES TO MOVE N/NNW AWAY FROM THE COASTAL
WATERS. WINDS WILL BE ON A DOWNWARD TREND...REMAINING NWRLY...EXCEPT
BECOMING ONSHORE IN THE AFTERNOON ALONG THE COAST WITH SEA BREEZE
DEVELOPMENT. SEAS WILL CONTINUE TO BE ELEVATED WITH SWELLS GENERATED
FROM THE NEARBY LOW PRESSURE SYSTEM. SUSPECT AN SCA WILL STILL BE
NECESSARY OVER THE OPEN ATLC FOR THE SEAS WITH EXERCISE CAUTION
STILL NECESSARY NEAR SHORE.
THU NIGHT-FRI NIGHT...LIGHT TO GENTLE WRLY BREEZE TO START FRI. THE
WEAK SFC PGRAD WILL ALLOW SFC WINDS TO SHIFT TO THE E/SE BY AFTN AS
THE EAST COAST SEA BREEZE DVLPS. AS THE STORM MOVES OVER OR NEAR THE
COASTAL CAROLINAS...THE ATLC RIDGE WILL REBUILD WWD INTO THE FL
STRAITS/S FL PENINSULA AFT SUNSET...ALLOWING WINDS TO SHIFT TO THE
S/SW. SEAS SUBSIDING TO 2-3FT NEAR SHORE/4-5FT OFFSHORE WILL SUBSIDE
BY ABOUT A FOOT AS SWELL IS PROGGED TO GRADUALLY DECAY...WITH A
MINIMAL WIND CHOP.
SAT-MON...ATLC RIDGE WILL BUILD SLOWLY NWD THRU THE WEEKEND AS THE
CAROLINA LOW CREEPS UP THE COAST. SRLY BREEZE WILL PREVAIL...
SHIFTING BTWN SW AND SE WITH THE FORMATION OF DIURNAL SEA BREEZES.
SEAS GENERALLY 2FT NEAR SHORE/3FT OFFSHORE...BUILDING BY A FOOT OR
SO EARLY NEXT WEEK AS SRLY FLOW ON THE WRN SIDE OF THE ATLC STARTS
TO FRESHEN.
CAVEAT WITH THIS FCST WILL BE THAT SHOULD THE LOW DEEPEN AS A STC OR
SC MORE THAN CURRENTLY PROGGED...IT WOULD SEND SOME HIGHER SWELLS
DOWN AT US INTO THE WEEKEND.
&&
.FIRE WEATHER...THU...DRIER AIR WILL FILTER DOWN THE PENINSULA ON
THE BACKSIDE OF THE RECENT LOW PRESSURE WITH AFTERNOON LOW MIN RH
VALUES FORECAST TO FALL INTO THE 30S OVER THE INTERIOR FROM OSCEOLA
COUNTY NORTHWARD. DISPERSION INDICES WILL BE GENERALLY GOOD IN THE
AFTERNOON. NW 20 FT WINDS IN UPWARDS OF AROUND 10 MPH...EXCEPT ALONG
THE COAST WHERE AN ONSHORE (NNE/NE) COMPONENT DEVELOPS IN THE
AFTERNOON. MUCH WARMER WITH HIGHS IN THE U80S ACROSS THE INTERIOR.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 63 82 64 84 / 20 0 10 10
MCO 66 87 64 87 / 10 0 10 10
MLB 65 83 64 86 / 20 0 10 10
VRB 65 85 64 87 / 20 0 10 10
LEE 65 87 64 86 / 10 0 10 10
SFB 65 89 63 87 / 10 0 10 10
ORL 67 86 66 87 / 10 0 10 10
FPR 62 85 62 89 / 20 0 10 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THURSDAY FOR FLAGLER BEACH
TO VOLUSIA-BREVARD COUNTY LINE 20-60 NM-SEBASTIAN INLET TO
JUPITER INLET 20-60 NM-VOLUSIA-BREVARD COUNTY LINE TO
SEBASTIAN INLET 20-60 NM.
&&
$$
LONG TERM/IMPACT WX...PENDERGRAST
SHORT TERM/AVIATION...WIMMER
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
245 PM CDT TUE MAY 5 2015
.UPDATE...
UPDATED TEMPERATURES AND WEATHER FOR THE REST OF TODAY. IT APPEARS
THE BEST CHANCES FOR SHOWERS AND THUNDERSTORM REDEVELOPMENT THIS
AFTERNOON WILL BE PRIMARILY ALONG AND SOUTH OF INTERSTATE 80 IN
CLOSER PROXIMATE TO THE NORTHWARD ADVANCING SURFACE BOUNDARY.
TEMPERATURES ACROSS CENTRAL ILLINOIS..SOUTH OF THIS BOUNDARY ARE
ALREADY WELL INTO THE 70S TO NEAR 80 IN MANY LOCATIONS...WITH DEW
POINTS POOLING INTO THE LOWER TO MID 60S RIGHT ALONG THE BOUNDARY.
MODIFYING THE 12 UTC ILX SOUNDING WITH THESE SURFACE CONDITIONS
YIELDS SCAPE AROUND 1300 J/KG WITH VERY LITTLE CAP. WITH THIS IN
MIND...IN SPITE OF THE FACT THAT THERE IS NO SIGNIFICANT MID LEVEL
DISTURBANCE EXPECTED TO MOVE OVER THE AREA THIS AFTERNOON...IT
SEEMS PROBABLE THAT SCT CONVECTION WILL STILL CONTINUE TO BUBBLE
UP THIS AFTERNOON WITHIN THE VICINTY OF THIS SURFACE
BOUNDARY...WHERE INSTABILITY AND SURFACE CONVERGENCE WILL BE
MAXIMIZED. FARTHER NORTH...VERY COOL AND STABLE CONDITIONS SHOULD
LIMIT SHOWER AND THUNDERSTORM POTENTIAL. THEREFORE...I HAVE
POINTED THE FORECAST IN THIS DIRECTION.
TEMPERATURES ACROSS MUCH OF THE CHICAGO AREA NEAR LAKE MICHGAN
WILL LIKELY REMAIN IN THE LOW TO MID 50S TODAY. HOWEVER...FARTHER
INLAND AND SOUTH...EXPECT TEMPERATURES WELL INTO THE
70S...ESPECIALLY SOUTH OF INTERSTATE 80.
KJB
&&
.SHORT TERM...
329 AM CDT
THROUGH TONIGHT...
A LOOSELY-DEFINED AND NON-INTENSE MCS IS MOVING ACROSS NORTHERN
ILLINOIS DURING THE PREDAWN WITHIN A BROAD ZONE OF WARM ADVECTION.
RADAR MOSAIC AND VAD WIND PROFILER DATA INDICATE THE PRESENCE OF
A MID-LEVEL SHORT WAVE THAT LIKELY MAY BE CONVECTIVELY-ENHANCED
HELPING TO FOCUS THE BULK OF THE RAIN AND EMBEDDED THUNDER. BASED
ON RADAR TRENDS...HAVE GONE A LITTLE FURTHER SOUTH WITH RAIN AND
THUNDER CHANCES THROUGH 9 AM OR SO COMPARED TO THE SUITE OF HIGH-
RESOLUTION GUIDANCE. OVERALL EXPECT THE COVERAGE OF PRECIPITATION
TO CONSIDERABLY DIMINISH DURING THE MID TO LATE MORNING HOURS
WITH THE WAVE PASSING NORTHEAST. TRAILING SHOWERS AND A FEW
STORMS ARE LIKELY TO LINGER ALONG AND NORTH OF I-80 DURING THE
LATTER MORNING.
WHILE THE MID-LEVEL FLOW IS EXPECTED TO BECOME LESS DISTURBED BY
AFTERNOON PER WATER VAPOR ANALYSIS AND RAP AND NAM
FORECASTS...THE CHANCES FOR AFTERNOON CONVECTION LINGER IN THE
HIGH PWAT AIR /1.4 INCHES +/. THESE CHANCES WILL BE ATTACHED TO
OUTFLOWS/CONVERGENCE ZONES TRAILING THE MORNING SHORT WAVE AND
ITS CONVECTION...AS WELL AS THE SYNOPTIC CONVERGENCE ALONG THE
STATIONARY FRONT THAT EARLY THIS MORNING IS ROUGHLY NEAR I-74.
THIS FEATURE IS EXPECTED TO CREEP NORTHWARD THIS MORNING WITH THE
DECAY OF CONVECTION AND HEATING IN THE WARM SECTOR. THIS FRONT
WILL SEPARATE TEMPERATURES LIKELY AROUND 80 IN THE SOUTHERN
FORECAST AREA TO THE COOLER AND CLOUDY 60S IN NORTHEAST
ILLINOIS...WITH EVEN LOWER TO MID 50S ALONG THE LAKE SHORE. DEW
POINTS IN THE LOWER-MID 60S ALONG THE BOUNDARY WILL PROVIDE
MARGINAL BUT SOME MIXED LAYER INSTABILITY NEAR THE BOUNDARY THIS
AFTERNOON. CONVECTIVE ALLOWING MODELS GENERALLY SHOW DEVELOPMENT
THIS AFTERNOON BUT VARY WIDELY IN COVERAGE. WITH WEAK MID-LEVEL
FLOW AND BUILDING HEIGHTS NOT EXPECTING ANYTHING SEVERE AND HAVE
GONE WITH SCATTERED OR CHANCE WORDING DEPENDING ON THE AREA. THE
PRESENT MOST FAVORED FOCUS THIS AFTERNOON LOOKS TO BE ALONG I-80
AND JUST NORTH OF...BUT THAT COULD CERTAINLY SHIFT OR BE MORE
DIFFUSE...AND THE DAY SHIFT WILL BE ABLE TO BETTER ASSESS POST-
MORNING CONVECTIVE TRENDS.
MODELS AGREE ANY SHOWERS/STORMS THIS AFTERNOON WILL WANE IN THE
EVENING BEING MORE DIURNALLY DRIVEN. THE FRONTAL BOUNDARY WILL
LIKELY NOT MAKE TOO MUCH PROGRESS NORTH DURING THE
NIGHT...HANGING AROUND I-80 OR SO. THE HIGH ABSOLUTE MOISTURE
ALONG THE BOUNDARY COULD RESULT IN FOG ACROSS THE AREA...SOME OF
WHICH MAY BE DENSE AND LINGER INTO EARLY WEDNESDAY MORNING. HAVE
ADDED SOME GENERAL MENTION INTO THE FORECAST FOR THE TIME BEING.
MTF
&&
.LONG TERM...
329 AM CDT
WEDNESDAY NIGHT THROUGH MONDAY...
ATTENTION IN THE LONG RANGE IS FIRST ON THE IMPRESSIVE EARLY MAY
WARMTH THAT WILL MAKE IT FEEL LIKE SUMMER IN SOME PLACES WEDNESDAY
AND AREAWIDE THURSDAY AND POTENTIALLY FRIDAY TOO. THE UPPER JET
PATTERN COMING IN FROM THE PACIFIC ON WEDNESDAY INTO THURSDAY
CARVES A MORE AMPLIFIED PATTERN...FAVORING BUILDING HEIGHTS AND
LOW-LEVEL SOUTHERLY FLOW TO INCREASE. GIVEN ALREADY ABOVE-NORMAL
TEMPERATURES UP TO CENTRAL ILLINOIS IN RECENT DAYS...THIS SYNOPTIC
PATTERN WILL FAVOR REPLENISHING AND ADDING TO THAT WARMTH AS WELL
AS SPREADING IT NORTH.
THE FRONTAL BOUNDARY IS LIKELY TO BREAK DOWN SOMEWHAT ON WEDNESDAY
AS JUST BROAD SOUTHERLY FLOW BEGINS. THIS FLOW WILL NOT BE STRONG
ENOUGH TO PREVENT LAKE COOLED AIR TO LIKELY REMAIN OVER NORTHEAST
ILLINOIS AND POSSIBLY EVEN FAR NORTHWEST INDIANA. APART FROM THE
MID 60S TO MID 70S IN THESE AREAS...LOWER TO POSSIBLY MID 80S ARE
EXPECTED ACROSS THE SOUTHERN AND FAR WESTERN FORECAST AREA.
THURSDAY WILL SEE SOUTH-SOUTHWEST WINDS INCREASE ENOUGH TO PREVENT
ANY LAKE COOLING. A THERMAL RIDGE DEFINED BY 925MB TEMPERATURES
OF 18C-19C AND 850MB TEMPERATURES OF 13-14C. USING REANALYSIS DATA
SINCE 1979...WHEN THESE WARM OF TEMPERATURES HAVE BEEN EXPERIENCED
IN THE FIRST HALF OF MAY IT YIELDS AN AVERAGE HIGH OF 83 DEGREES
AT CHICAGO OHARE. WITH SUNSHINE HIGHLY LIKELY ON THURSDAY GIVEN
THE AMPLIFIED FLOW KEEPING CIRRUS/DEBRIS AWAY ON MODEL
SOLUTIONS...HAVE BOOSTED TEMPERATURES TO THESE VALUES AND EVEN
SLIGHTLY HIGHER. SOME UPPER 80S ARE CERTAINLY POSSIBLE GIVEN THIS
PATTERN. THE RECORD HIGH FOR CHICAGO ON THURSDAY MAY 7TH IS 87
DEGREES SET IN 1964.
THE SECOND FOCUS ON THE LONG RANGE IS CONVECTIVE CHANCES. THE
POTENTIAL BEGINS FRIDAY WITH A NORTHERN STREAM FRONT EASING TOWARD
THE AREA...WHICH WILL COOL TEMPERATURES FOR SATURDAY AND POSSIBLY
SUNDAY TOO...ESPECIALLY FOR LAKE ADJACENT AREAS. AS THE UPPER-
LEVEL SOUTHWESTERLY FLOW INCREASES LATER IN THE WEEKEND...STORM
CHANCES WILL INCREASE AS HIGH PWAT AIR IS AGAIN FORECAST TO
ESTABLISH ITSELF ACROSS THE CORN BELT REGION. TIMING OF SHOWERS
AND STORMS LOOK TO AGAIN BE TIED TO MID-LEVEL IMPULSES WHICH CAN
OFTEN BE SUBTLE...WHICH DIMINISHES PREDICTABILITY AT THIS
POINT...SO CONTINUE WITH CHANCES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* EAST-NORTHEAST WINDS AROUND 10 KT THROUGH THIS AFTERNOON.
* IFR/LIFR CIGS THROUGH THE BEGINNING OF THE MORNING RUSH
WEDNESDAY.
* IFR/LIFR VSBYS AT ORD THROUGH EARLY TOMORROW. RETURNING TO MDW
TONIGHT.
* SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM THIS AFTN...MAINLY SOUTH
OF MDW.
KMD
//DISCUSSION...UPDATED 18Z...
THE BATTLE OF THE COLD LAKE AND LOW LEVEL ONSHORE FLOW VERSUS THE
WARM MAY SUN IS UNDERWAY...MAKING FOR A CHALLENGING AFTERNOON
FORECAST ACROSS THE TERMINALS. MONITORING WEBCAMS DOWNTOWN SHOW
CLOUDS BRIEFLY ATTEMPTING TO LIFT BEFORE FILLING RIGHT BACK IN. WE
ALSO CONTINUE TO ADVECT WARMER AND MOIST AIR JUST OFF THE DECK
WHICH IS AIDING IN KEEPING THE LOW LEVEL INVERSION IN PLACE. FEEL
THAT THESE LATTER FACTORS WILL WIN OUT AND KEEP MOST OF THE TAF
SITES LOCKED IN LIFR TO IFR CONDITIONS...WHILE POINTS SOUTH WILL
LIFT TO VFR BEFORE MVFR CUMULUS FILL IN AS WELL.
THE LOW LEVEL FRONT IS NOT EXPECTED TO LIFT MUCH FARTHER
NORTH...AND THUS EXPECT THE NNE WINDS TO REMAIN IN PLACE. WITH THE
FRONT HOLDING SOUTH...EXPECT ANY CONVECTION THAT STIRS THIS
AFTERNOON TO BE FOCUSED IN THESE AREAS...SOUTH OF INTERSTATE 80.
TONIGHT WINDS SHOULD WEAKEN SOME AND EXPECT CIGS/VSBYS TO REMAIN
LOCKED IN DOWN LOW MOST OF THE NIGHT. FOG COULD BE DENSE
TONIGHT...ESPECIALLY CLOSER TO THE LAKE. LOW LEVEL FRONT GETS
SOME NORTHWARD MOVEMENT EARLY WEDS WHICH SHOULD ALLOW FOR SOME
LIFTING WEDNESDAY MORNING. PRECIP CHANCES DO EXIST TONIGHT/EARLY
WEDS BUT TOO LOW FOR A MENTION IN THE TAFS JUST YET. AT BEST SOME
ISOLATED SHOWERS AHEAD OF THE FRONT 8Z-12Z TIME FRAME FOR THE TAF
SITES.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH THAT EAST-NORTHEAST WINDS HOLD AROUND 10 KT THIS AFTERNOON.
* HIGH IN LIFR CIGS HOLDING AT ORD... AND IFR/LIFR CIGS RETURNING
TO MDW. MEDIUM ON CIG HEIGHTS OVERNIGHT THOUGH LOW-MEDIUM ON
CLEARING TIME WEDS.
* MEDIUM-LOW ON VSBYS THIS AFTERNOON AND TONIGHT. COULD BE WORSE
VSBY OVERNIGHT.
* HIGH IN ORD REMAINING DRY THE REST OF THE DAY. MEDIUM THAT
AFTERNOON SHOWERS/ISOLATED T-STORMS REMAIN SOUTH OF MDW. MEDIUM
THAT TAF SITES REMAIN DRY OVERNIGHT AS WELL.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...VFR. SOUTHEAST WINDS BCMG SOUTH.
THURSDAY...VFR. SOUTH WINDS.
FRIDAY...TSRA. MVFR CIGS PSBL OVERNIGHT. SOUTHWEST WINDS.
SATURDAY...SCHC TSRA DURING THE DAY AND CHC SHRA. NORTHWEST WINDS.
SUNDAY AND MONDAY...CHC TSRA. MVFR CIGS PSBL. NORTHEAST WINDS BCMG
SOUTHWEST MONDAY.
JEE
&&
.MARINE...
212 AM CDT
A STATIONARY FRONT IS OVER CENTRAL IL AND IT WILL REMAIN SOUTH OF
THE LAKE UNTIL IT LIFTS NORTH AS A WARM FRONT WEDNESDAY.
THEREFORE...NORTHEAST TO EAST WINDS WILL BECOME SOUTH WEDNESDAY
NIGHT BEHIND THE WARM FRONT. HIGH PRESSURE CURRENTLY OVER LAKE
SUPERIOR SHIFTS EAST OF LAKE MICHIGAN WEDNESDAY AND REMAINS OVER THE
EASTERN SEABOARD THROUGH THE WEEK. SOUTH WINDS UP TO 20 KT AT TIMES
ARE EXPECTED THROUGH FRIDAY. THE NEXT LOW FORMS OVER THE NORTHERN
ROCKIES WEDNESDAY AND MOVES OVER ONTARIO THURSDAY NIGHT AND FRIDAY.
THE LOWS COLD FRONT SWEEPS OVER THE LAKE SATURDAY AND WINDS BECOME
NORTH BEHIND THE FRONT.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ006-ILZ014 UNTIL 11 AM WEDNESDAY.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-
LMZ777-LMZ779 UNTIL 4 PM WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
111 PM CDT TUE MAY 5 2015
.UPDATE...1135 AM CDT
UPDATED TEMPERATURES AND WEATHER FOR THE REST OF TODAY. IT APPEARS
THE BEST CHANCES FOR SHOWERS AND THUNDERSTORM REDEVELOPMENT THIS
AFTERNOON WILL BE PRIMARILY ALONG AND SOUTH OF INTERSTATE 80 IN
CLOSER PROXIMATE TO THE NORTHWARD ADVANCING SURFACE BOUNDARY.
TEMPERATURES ACROSS CENTRAL ILLINOIS..SOUTH OF THIS BOUNDARY ARE
ALREADY WELL INTO THE 70S TO NEAR 80 IN MANY LOCATIONS...WITH DEW
POINTS POOLING INTO THE LOWER TO MID 60S RIGHT ALONG THE BOUNDARY.
MODIFYING THE 12 UTC ILX SOUNDING WITH THESE SURFACE CONDITIONS
YIELDS SCAPE AROUND 1300 J/KG WITH VERY LITTLE CAP. WITH THIS IN
MIND...IN SPITE OF THE FACT THAT THERE IS NO SIGNIFICANT MID LEVEL
DISTURBANCE EXPECTED TO MOVE OVER THE AREA THIS AFTERNOON...IT
SEEMS PROBABLE THAT SCT CONVECTION WILL STILL CONTINUE TO BUBBLE
UP THIS AFTERNOON WITHIN THE VICINTY OF THIS SURFACE
BOUNDARY...WHERE INSTABILITY AND SURFACE CONVERGENCE WILL BE
MAXIMIZED. FARTHER NORTH...VERY COOL AND STABLE CONDITIONS SHOULD
LIMIT SHOWER AND THUNDERSTORM POTENTIAL. THEREFORE...I HAVE
POINTED THE FORECAST IN THIS DIRECTION.
TEMPERATURES ACROSS MUCH OF THE CHICAGO AREA NEAR LAKE MICHGAN
WILL LIKELY REMAIN IN THE LOW TO MID 50S TODAY. HOWEVER...FARTHER
INLAND AND SOUTH...EXPECT TEMPERATURES WELL INTO THE
70S...ESPECIALLY SOUTH OF INTERSTATE 80.
KJB
&&
.SHORT TERM...
329 AM CDT
THROUGH TONIGHT...
A LOOSELY-DEFINED AND NON-INTENSE MCS IS MOVING ACROSS NORTHERN
ILLINOIS DURING THE PREDAWN WITHIN A BROAD ZONE OF WARM ADVECTION.
RADAR MOSAIC AND VAD WIND PROFILER DATA INDICATE THE PRESENCE OF
A MID-LEVEL SHORT WAVE THAT LIKELY MAY BE CONVECTIVELY-ENHANCED
HELPING TO FOCUS THE BULK OF THE RAIN AND EMBEDDED THUNDER. BASED
ON RADAR TRENDS...HAVE GONE A LITTLE FURTHER SOUTH WITH RAIN AND
THUNDER CHANCES THROUGH 9 AM OR SO COMPARED TO THE SUITE OF HIGH-
RESOLUTION GUIDANCE. OVERALL EXPECT THE COVERAGE OF PRECIPITATION
TO CONSIDERABLY DIMINISH DURING THE MID TO LATE MORNING HOURS
WITH THE WAVE PASSING NORTHEAST. TRAILING SHOWERS AND A FEW
STORMS ARE LIKELY TO LINGER ALONG AND NORTH OF I-80 DURING THE
LATTER MORNING.
WHILE THE MID-LEVEL FLOW IS EXPECTED TO BECOME LESS DISTURBED BY
AFTERNOON PER WATER VAPOR ANALYSIS AND RAP AND NAM
FORECASTS...THE CHANCES FOR AFTERNOON CONVECTION LINGER IN THE
HIGH PWAT AIR /1.4 INCHES +/. THESE CHANCES WILL BE ATTACHED TO
OUTFLOWS/CONVERGENCE ZONES TRAILING THE MORNING SHORT WAVE AND
ITS CONVECTION...AS WELL AS THE SYNOPTIC CONVERGENCE ALONG THE
STATIONARY FRONT THAT EARLY THIS MORNING IS ROUGHLY NEAR I-74.
THIS FEATURE IS EXPECTED TO CREEP NORTHWARD THIS MORNING WITH THE
DECAY OF CONVECTION AND HEATING IN THE WARM SECTOR. THIS FRONT
WILL SEPARATE TEMPERATURES LIKELY AROUND 80 IN THE SOUTHERN
FORECAST AREA TO THE COOLER AND CLOUDY 60S IN NORTHEAST
ILLINOIS...WITH EVEN LOWER TO MID 50S ALONG THE LAKE SHORE. DEW
POINTS IN THE LOWER-MID 60S ALONG THE BOUNDARY WILL PROVIDE
MARGINAL BUT SOME MIXED LAYER INSTABILITY NEAR THE BOUNDARY THIS
AFTERNOON. CONVECTIVE ALLOWING MODELS GENERALLY SHOW DEVELOPMENT
THIS AFTERNOON BUT VARY WIDELY IN COVERAGE. WITH WEAK MID-LEVEL
FLOW AND BUILDING HEIGHTS NOT EXPECTING ANYTHING SEVERE AND HAVE
GONE WITH SCATTERED OR CHANCE WORDING DEPENDING ON THE AREA. THE
PRESENT MOST FAVORED FOCUS THIS AFTERNOON LOOKS TO BE ALONG I-80
AND JUST NORTH OF...BUT THAT COULD CERTAINLY SHIFT OR BE MORE
DIFFUSE...AND THE DAY SHIFT WILL BE ABLE TO BETTER ASSESS POST-
MORNING CONVECTIVE TRENDS.
MODELS AGREE ANY SHOWERS/STORMS THIS AFTERNOON WILL WANE IN THE
EVENING BEING MORE DIURNALLY DRIVEN. THE FRONTAL BOUNDARY WILL
LIKELY NOT MAKE TOO MUCH PROGRESS NORTH DURING THE
NIGHT...HANGING AROUND I-80 OR SO. THE HIGH ABSOLUTE MOISTURE
ALONG THE BOUNDARY COULD RESULT IN FOG ACROSS THE AREA...SOME OF
WHICH MAY BE DENSE AND LINGER INTO EARLY WEDNESDAY MORNING. HAVE
ADDED SOME GENERAL MENTION INTO THE FORECAST FOR THE TIME BEING.
MTF
&&
.LONG TERM...
329 AM CDT
WEDNESDAY NIGHT THROUGH MONDAY...
ATTENTION IN THE LONG RANGE IS FIRST ON THE IMPRESSIVE EARLY MAY
WARMTH THAT WILL MAKE IT FEEL LIKE SUMMER IN SOME PLACES WEDNESDAY
AND AREAWIDE THURSDAY AND POTENTIALLY FRIDAY TOO. THE UPPER JET
PATTERN COMING IN FROM THE PACIFIC ON WEDNESDAY INTO THURSDAY
CARVES A MORE AMPLIFIED PATTERN...FAVORING BUILDING HEIGHTS AND
LOW-LEVEL SOUTHERLY FLOW TO INCREASE. GIVEN ALREADY ABOVE-NORMAL
TEMPERATURES UP TO CENTRAL ILLINOIS IN RECENT DAYS...THIS SYNOPTIC
PATTERN WILL FAVOR REPLENISHING AND ADDING TO THAT WARMTH AS WELL
AS SPREADING IT NORTH.
THE FRONTAL BOUNDARY IS LIKELY TO BREAK DOWN SOMEWHAT ON WEDNESDAY
AS JUST BROAD SOUTHERLY FLOW BEGINS. THIS FLOW WILL NOT BE STRONG
ENOUGH TO PREVENT LAKE COOLED AIR TO LIKELY REMAIN OVER NORTHEAST
ILLINOIS AND POSSIBLY EVEN FAR NORTHWEST INDIANA. APART FROM THE
MID 60S TO MID 70S IN THESE AREAS...LOWER TO POSSIBLY MID 80S ARE
EXPECTED ACROSS THE SOUTHERN AND FAR WESTERN FORECAST AREA.
THURSDAY WILL SEE SOUTH-SOUTHWEST WINDS INCREASE ENOUGH TO PREVENT
ANY LAKE COOLING. A THERMAL RIDGE DEFINED BY 925MB TEMPERATURES
OF 18C-19C AND 850MB TEMPERATURES OF 13-14C. USING REANALYSIS DATA
SINCE 1979...WHEN THESE WARM OF TEMPERATURES HAVE BEEN EXPERIENCED
IN THE FIRST HALF OF MAY IT YIELDS AN AVERAGE HIGH OF 83 DEGREES
AT CHICAGO OHARE. WITH SUNSHINE HIGHLY LIKELY ON THURSDAY GIVEN
THE AMPLIFIED FLOW KEEPING CIRRUS/DEBRIS AWAY ON MODEL
SOLUTIONS...HAVE BOOSTED TEMPERATURES TO THESE VALUES AND EVEN
SLIGHTLY HIGHER. SOME UPPER 80S ARE CERTAINLY POSSIBLE GIVEN THIS
PATTERN. THE RECORD HIGH FOR CHICAGO ON THURSDAY MAY 7TH IS 87
DEGREES SET IN 1964.
THE SECOND FOCUS ON THE LONG RANGE IS CONVECTIVE CHANCES. THE
POTENTIAL BEGINS FRIDAY WITH A NORTHERN STREAM FRONT EASING TOWARD
THE AREA...WHICH WILL COOL TEMPERATURES FOR SATURDAY AND POSSIBLY
SUNDAY TOO...ESPECIALLY FOR LAKE ADJACENT AREAS. AS THE UPPER-
LEVEL SOUTHWESTERLY FLOW INCREASES LATER IN THE WEEKEND...STORM
CHANCES WILL INCREASE AS HIGH PWAT AIR IS AGAIN FORECAST TO
ESTABLISH ITSELF ACROSS THE CORN BELT REGION. TIMING OF SHOWERS
AND STORMS LOOK TO AGAIN BE TIED TO MID-LEVEL IMPULSES WHICH CAN
OFTEN BE SUBTLE...WHICH DIMINISHES PREDICTABILITY AT THIS
POINT...SO CONTINUE WITH CHANCES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* EAST-NORTHEAST WINDS AROUND 10 KT THROUGH THIS AFTERNOON.
* IFR/LIFR CIGS THROUGH THE BEGINNING OF THE MORNING RUSH
WEDNESDAY.
* IFR/LIFR VSBYS RETURNING TONIGHT.
* SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM THIS AFTN...MAINLY SOUTH
OF MDW.
KMD
//DISCUSSION...UPDATED 18Z...
THE BATTLE OF THE COLD LAKE AND LOW LEVEL ONSHORE FLOW VERSUS THE
WARM MAY SUN IS UNDERWAY...MAKING FOR A CHALLENGING AFTERNOON
FORECAST ACROSS THE TERMINALS. MONITORING WEBCAMS DOWNTOWN SHOW
CLOUDS BRIEFLY ATTEMPTING TO LIFT BEFORE FILLING RIGHT BACK IN. WE
ALSO CONTINUE TO ADVECT WARMER AND MOIST AIR JUST OFF THE DECK
WHICH IS AIDING IN KEEPING THE LOW LEVEL INVERSION IN PLACE. FEEL
THAT THESE LATTER FACTORS WILL WIN OUT AND KEEP MOST OF THE TAF
SITES LOCKED IN LIFR TO IFR CONDITIONS...WHILE POINTS SOUTH WILL
LIFT TO VFR BEFORE MVFR CUMULUS FILL IN AS WELL.
THE LOW LEVEL FRONT IS NOT EXPECTED TO LIFT MUCH FARTHER
NORTH...AND THUS EXPECT THE NNE WINDS TO REMAIN IN PLACE. WITH THE
FRONT HOLDING SOUTH...EXPECT ANY CONVECTION THAT STIRS THIS
AFTERNOON TO BE FOCUSED IN THESE AREAS...SOUTH OF INTERSTATE 80.
TONIGHT WINDS SHOULD WEAKEN SOME AND EXPECT CIGS/VSBYS TO REMAIN
LOCKED IN DOWN LOW MOST OF THE NIGHT. FOG COULD BE DENSE
TONIGHT...ESPECIALLY CLOSER TO THE LAKE. LOW LEVEL FRONT GETS
SOME NORTHWARD MOVEMENT EARLY WEDS WHICH SHOULD ALLOW FOR SOME
LIFTING WEDNESDAY MORNING. PRECIP CHANCES DO EXIST TONIGHT/EARLY
WEDS BUT TOO LOW FOR A MENTION IN THE TAFS JUST YET. AT BEST SOME
ISOLATED SHOWERS AHEAD OF THE FRONT 8Z-12Z TIME FRAME FOR THE TAF
SITES.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH THAT EAST-NORTHEAST WINDS HOLD AROUND 10 KT THIS AFTERNOON.
* HIGH IN LIFR CIGS HOLDING OR LIFTING SLIGHTLY AT ORD... AND
IFR/LIFR CIGS RETURNING TO MDW. MEDIUM ON CIG HEIGHTS OVERNIGHT
THOUGH LOW-MEDIUM ON CLEARING TIME WEDS.
* MEDIUM-LOW ON VSBYS THIS AFTERNOON AND TONIGHT. COULD BE WORSE
VSBY OVERNIGHT.
* HIGH IN ORD REMAINING DRY THE REST OF THE DAY. MEDIUM-HIGH THAT
AFTERNOON SHOWERS/ISOLATED T-STORMS REMAIN SOUTH OF MDW. MEDIUM
THAT TAF SITES REMAIN DRY OVERNIGHT AS WELL.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...VFR. SOUTHEAST WINDS BCMG SOUTH.
THURSDAY...VFR. SOUTH WINDS.
FRIDAY...TSRA. MVFR CIGS PSBL OVERNIGHT. SOUTHWEST WINDS.
SATURDAY...SCHC TSRA DURING THE DAY AND CHC SHRA. NORTHWEST WINDS.
SUNDAY AND MONDAY...CHC TSRA. MVFR CIGS PSBL. NORTHEAST WINDS BCMG
SOUTHWEST MONDAY.
JEE
&&
.MARINE...
212 AM CDT
A STATIONARY FRONT IS OVER CENTRAL IL AND IT WILL REMAIN SOUTH OF
THE LAKE UNTIL IT LIFTS NORTH AS A WARM FRONT WEDNESDAY.
THEREFORE...NORTHEAST TO EAST WINDS WILL BECOME SOUTH WEDNESDAY
NIGHT BEHIND THE WARM FRONT. HIGH PRESSURE CURRENTLY OVER LAKE
SUPERIOR SHIFTS EAST OF LAKE MICHIGAN WEDNESDAY AND REMAINS OVER THE
EASTERN SEABOARD THROUGH THE WEEK. SOUTH WINDS UP TO 20 KT AT TIMES
ARE EXPECTED THROUGH FRIDAY. THE NEXT LOW FORMS OVER THE NORTHERN
ROCKIES WEDNESDAY AND MOVES OVER ONTARIO THURSDAY NIGHT AND FRIDAY.
THE LOWS COLD FRONT SWEEPS OVER THE LAKE SATURDAY AND WINDS BECOME
NORTH BEHIND THE FRONT.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1249 PM CDT TUE MAY 5 2015
.UPDATE...
ISSUED AT 1045 AM CDT TUE MAY 5 2015
15Z/10AM SURFACE ANALYSIS SHOWS FRONTAL BOUNDARY EXTENDING FROM
NORTH-CENTRAL ILLINOIS INTO CENTRAL IOWA...GENERALLY ALONG A
KANKAKEE...TO PEORIA...TO DES MOINES LINE. WIDESPREAD RAIN
CONTINUES TO FALL NORTH OF THE FRONT: HOWEVER, MOSTLY SUNNY AND
DRY CONDITIONS PREVAIL TO THE SOUTH ACROSS CENTRAL ILLINOIS.
TEMPERATURES HAVE ALREADY RISEN WELL INTO THE 70S ACROSS ALL BUT
THE FAR NORTHERN KILX CWA. BASED ON THE 12Z UPPER AIR SOUNDING AND
ASSUMING MIXING UP TO ABOUT 750MB SIMILAR TO YESTERDAY
AFTERNOON...HIGHS TODAY SHOULD REACH THE LOWER TO MIDDLE 80S. HAVE
ADJUSTED TEMPS UP BY A FEW DEGREES ACCORDINGLY.
&&
.SHORT TERM...(TODAY)
ISSUED AT 332 AM CDT TUE MAY 5 2015
A FRONTAL BOUNDARY IS ORIENTED WEST-EAST ACROSS CENTRAL IL THIS
MORNING WITH PRECIPITATION IN ISENTROPIC ASCENT REGION LARGELY TO
THE NORTH OF THE BOUNDARY. MODELS INDICATE THE BOUNDARY AND
PRECIPITATION WILL SHIFT SLOWLY NORTHWARD TODAY. WEAK DISTURBANCES
MOVING ALONG THE BOUNDARY WILL PRODUCE SOME ENHANCEMENTS IN
CONVECTIVE SHOWER COVERAGE IN THE VICINITY...EARLY THIS MORNING FROM
AROUND THE ILLINOIS RIVER NORTHWESTWARD...AND LATE IN THE AFTERNOON
NORTH OF THE I-74 CORRIDOR. FOR THE MOST PART...CONVECTION SHOULD BE
WEAK AT THIS POINT WITH ONLY WEAK MID-LEVEL INSTABILITY REMAINING
THROUGH THE NIGHT...AND 0-6KM BULK SHEAR UP TO 25-30 KTS THIS
MORNING DIMINISHING SUBSTANTIALLY FOR THE AFTERNOON. 1000-1500
JOULES OF SURFACE-BASED CAPE SHOULD BE ABLE TO DEVELOP WITH
AFTERNOON HEATING ALONG/NORTH OF I-72 AND CAN`T RULE OUT ISOLATED
THUNDERSTORMS SOUTHWARD TO I-72 AS A RESULT.
.LONG TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 332 AM CDT TUE MAY 5 2015
ONGOING CONVECTION ALONG THE BOUNDARY OVER NORTHERN ILLINOIS THIS
MORNING NOT ONLY DRIVING THE WEATHER THROUGHOUT THE DAY, BUT INTO
THE OVERNIGHT AS WELL. GFS AND NAM CONTINUE TO KEEP A BIT OF PRECIP
PRETTY FAR SOUTH, AS FAR SOUTH AS A LINE FROM HAVANA TO BLOOMINGTON.
HOWEVER, THE RAP/RUC AND THE HRRR ARE PUSHING THE AREA OF CONVECTION
WELL TO THE NORTH THROUGH THE MORNING WITH THE BOUNDARY. WHEN THE
SECONDARY WAVE RIPPLES THROUGH THE REGION AFTER 00Z, IT WOULD BE
DISPLACED NORTH OF THE FA. THE 4KM WRF HAS JUST THAT SOLUTION,
STARTING MORE IN LINE WITH THE RAP/RUC AND HRRR...AND KEEPING THE FA
DRY AFTER 00Z, BUT A LITTLE MORE GENEROUS WITH SOME ISOLATED
INSTABILITY SHOWERS. HAVE KEPT ISO TS IN THE NORTH, MAINLY ALONG
AND NORTH OF I-74 FOR THE EARLY EVENING.
HIGH PRESSURE BEGINS TO BUILD BACK INTO THE REGION LATER TONIGHT,
SOUTHERLY WINDS PUSHING THE FRONT BACK TO THE NORTH AND OUT OF THE
FORECAST AREA THROUGH WED NIGHT. FORECAST REMAINS ROUGHLY THE SAME
BEYOND DAY 3... PRECIP CHANCES SLOWLY EDGING BACK INTO WEST CENTRAL
ILLINOIS FOR THURSDAY AS AN UPPER LEVEL WAVE PUSHES OUT OF THE SW.
THE ENERGY IS PART OF A GENERAL PATTERN SHIFT TO MORE SOUTHWESTERLY
FLOW WITH THE UPPER LEVEL TROF DIGGING BACK IN OVER THE SWRN CONUS.
THE SFC LOW MOVES OUT INTO THE UPPER MIDWEST AND INTO CANADA BY THE
END OF THE WEEK, BUT IN SHIFTING TO MORE SOUTHWESTERLY FLOW ALOFT,
OPENS THE DOOR TO A SERIES OF SHORTWAVES THAT KEEP THE FORECAST WET
FOR THE END OF THE WORK WEEK AND INTO THE WEEKEND. TEMPS RATHER
WARM THROUGH THE FORECAST WITH OVERCAST AND RAINY SKIES KEEPING THE
OVERNIGHT LOWS UP A BIT, BUT LIKELY NOT NEARLY AS WARM AS THE TREND
IN THE GUIDANCE. HAVE KNOCKED THEM DOWN A COUPLE DEGREES. SOUTHERLY
FLOW AND A RELATIVELY WARM AIRMASS KEEPING THE HIGHS A BIT ABOVE
NORMS, EVEN WITH THE PASSAGE OF THE FIRST LOW SKIRTING TO THE
NW...THE MID LEVELS REMAIN WARM UNTIL THE MAIN TROF OVER THE SW
LIFTS INTO AND OUT OF THE GREAT LAKES. COOLER AIR IN THE MIDLEVELS
IS ONLY AROUND FOR 36 HOURS DAY 7/8 BEFORE THE WARM AIRMASS
REESTABLISHES ITSELF.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1249 PM CDT TUE MAY 5 2015
LATEST SURFACE ANALYSIS CONTINUES TO SHOW NEARLY STATIONARY
FRONTAL BOUNDARY DRAPED ACROSS NORTH-CENTRAL ILLINOIS FROM JUST
NORTH OF KGBG TO SOUTH OF KPNT. WINDS IN THE VICINITY OF THE
BOUNDARY ARE LIGHT/VARIABLE AT KPIA...BUT ARE SOUTHWESTERLY AT 10
TO 15KT FURTHER SOUTH AT THE REMAINING TERMINALS. HIGH-RES MODELS
SUGGEST THE FRONT WILL SINK SLIGHTLY SOUTHWARD LATER THIS
AFTERNOON AND EVENING...RESULTING IN A WIND SHIFT TO THE E/NE AT
BOTH KPIA AND KBMI. MODELS DIFFER ON THE EXACT TIMING...WITH THE
HRRR SHOWING THE SHIFT AT ABOUT 22Z. AFTER THAT...THE FRONT WILL
REMAIN IN PLACE ALONG/JUST SOUTH OF I-74 THROUGHOUT THE NIGHT.
HAVE CONTINUED WITH A LIGHT E/NE WIND AT KPIA AND KBMI
ACCORDINGLY...WITH SOUTHERLY WINDS AT KSPI AND KDEC. THE FRONT
WILL FINALLY GET A SOLID PUSH NORTHWARD BY WEDNESDAY
MORNING...ALLOWING WINDS TO BECOME SOUTHERLY AT ALL TAF SITES.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARNES
SHORT TERM...ONTON
LONG TERM...HJS
AVIATION...BARNES
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1150 AM CDT TUE MAY 5 2015
.UPDATE...
1135 AM CDT
UPDATED TEMPERATURES AND WEATHER FOR THE REST OF TODAY. IT APPEARS
THE BEST CHANCES FOR SHOWERS AND THUNDERSTORM REDEVELOPMENT THIS
AFTERNOON WILL BE PRIMARILY ALONG AND SOUTH OF INTERSTATE 80 IN
CLOSER PROXIMATE TO THE NORTHWARD ADVANCING SURFACE BOUNDARY.
TEMPERATURES ACROSS CENTRAL ILLINOIS..SOUTH OF THIS BOUNDARY ARE
ALREADY WELL INTO THE 70S TO NEAR 80 IN MANY LOCATIONS...WITH DEW
POINTS POOLING INTO THE LOWER TO MID 60S RIGHT ALONG THE BOUNDARY.
MODIFYING THE 12 UTC ILX SOUNDING WITH THESE SURFACE CONDITIONS
YIELDS SCAPE AROUND 1300 J/KG WITH VERY LITTLE CAP. WITH THIS IN
MIND...IN SPITE OF THE FACT THAT THERE IS NO SIGNIFICANT MID LEVEL
DISTURBANCE EXPECTED TO MOVE OVER THE AREA THIS AFTERNOON...IT
SEEMS PROBABLE THAT SCT CONVECTION WILL STILL CONTINUE TO BUBBLE
UP THIS AFTERNOON WITHIN THE VICINTY OF THIS SURFACE
BOUNDARY...WHERE INSTABILITY AND SURFACE CONVERGENCE WILL BE
MAXIMIZED. FARTHER NORTH...VERY COOL AND STABLE CONDITIONS SHOULD
LIMIT SHOWER AND THUNDERSTORM POTENTIAL. THEREFORE...I HAVE
POINTED THE FORECAST IN THIS DIRECTION.
TEMPERATURES ACROSS MUCH OF THE CHICAGO AREA NEAR LAKE MICHGAN
WILL LIKELY REMAIN IN THE LOW TO MID 50S TODAY. HOWEVER...FARTHER
INLAND AND SOUTH...EXPECT TEMPERATURES WELL INTO THE
70S...ESPECIALLY SOUTH OF INTERSTATE 80.
KJB
&&
.SHORT TERM...
329 AM CDT
THROUGH TONIGHT...
A LOOSELY-DEFINED AND NON-INTENSE MCS IS MOVING ACROSS NORTHERN
ILLINOIS DURING THE PREDAWN WITHIN A BROAD ZONE OF WARM ADVECTION.
RADAR MOSAIC AND VAD WIND PROFILER DATA INDICATE THE PRESENCE OF
A MID-LEVEL SHORT WAVE THAT LIKELY MAY BE CONVECTIVELY-ENHANCED
HELPING TO FOCUS THE BULK OF THE RAIN AND EMBEDDED THUNDER. BASED
ON RADAR TRENDS...HAVE GONE A LITTLE FURTHER SOUTH WITH RAIN AND
THUNDER CHANCES THROUGH 9 AM OR SO COMPARED TO THE SUITE OF HIGH-
RESOLUTION GUIDANCE. OVERALL EXPECT THE COVERAGE OF PRECIPITATION
TO CONSIDERABLY DIMINISH DURING THE MID TO LATE MORNING HOURS
WITH THE WAVE PASSING NORTHEAST. TRAILING SHOWERS AND A FEW
STORMS ARE LIKELY TO LINGER ALONG AND NORTH OF I-80 DURING THE
LATTER MORNING.
WHILE THE MID-LEVEL FLOW IS EXPECTED TO BECOME LESS DISTURBED BY
AFTERNOON PER WATER VAPOR ANALYSIS AND RAP AND NAM
FORECASTS...THE CHANCES FOR AFTERNOON CONVECTION LINGER IN THE
HIGH PWAT AIR /1.4 INCHES +/. THESE CHANCES WILL BE ATTACHED TO
OUTFLOWS/CONVERGENCE ZONES TRAILING THE MORNING SHORT WAVE AND
ITS CONVECTION...AS WELL AS THE SYNOPTIC CONVERGENCE ALONG THE
STATIONARY FRONT THAT EARLY THIS MORNING IS ROUGHLY NEAR I-74.
THIS FEATURE IS EXPECTED TO CREEP NORTHWARD THIS MORNING WITH THE
DECAY OF CONVECTION AND HEATING IN THE WARM SECTOR. THIS FRONT
WILL SEPARATE TEMPERATURES LIKELY AROUND 80 IN THE SOUTHERN
FORECAST AREA TO THE COOLER AND CLOUDY 60S IN NORTHEAST
ILLINOIS...WITH EVEN LOWER TO MID 50S ALONG THE LAKE SHORE. DEW
POINTS IN THE LOWER-MID 60S ALONG THE BOUNDARY WILL PROVIDE
MARGINAL BUT SOME MIXED LAYER INSTABILITY NEAR THE BOUNDARY THIS
AFTERNOON. CONVECTIVE ALLOWING MODELS GENERALLY SHOW DEVELOPMENT
THIS AFTERNOON BUT VARY WIDELY IN COVERAGE. WITH WEAK MID-LEVEL
FLOW AND BUILDING HEIGHTS NOT EXPECTING ANYTHING SEVERE AND HAVE
GONE WITH SCATTERED OR CHANCE WORDING DEPENDING ON THE AREA. THE
PRESENT MOST FAVORED FOCUS THIS AFTERNOON LOOKS TO BE ALONG I-80
AND JUST NORTH OF...BUT THAT COULD CERTAINLY SHIFT OR BE MORE
DIFFUSE...AND THE DAY SHIFT WILL BE ABLE TO BETTER ASSESS POST-
MORNING CONVECTIVE TRENDS.
MODELS AGREE ANY SHOWERS/STORMS THIS AFTERNOON WILL WANE IN THE
EVENING BEING MORE DIURNALLY DRIVEN. THE FRONTAL BOUNDARY WILL
LIKELY NOT MAKE TOO MUCH PROGRESS NORTH DURING THE
NIGHT...HANGING AROUND I-80 OR SO. THE HIGH ABSOLUTE MOISTURE
ALONG THE BOUNDARY COULD RESULT IN FOG ACROSS THE AREA...SOME OF
WHICH MAY BE DENSE AND LINGER INTO EARLY WEDNESDAY MORNING. HAVE
ADDED SOME GENERAL MENTION INTO THE FORECAST FOR THE TIME BEING.
MTF
&&
.LONG TERM...
329 AM CDT
WEDNESDAY NIGHT THROUGH MONDAY...
ATTENTION IN THE LONG RANGE IS FIRST ON THE IMPRESSIVE EARLY MAY
WARMTH THAT WILL MAKE IT FEEL LIKE SUMMER IN SOME PLACES WEDNESDAY
AND AREAWIDE THURSDAY AND POTENTIALLY FRIDAY TOO. THE UPPER JET
PATTERN COMING IN FROM THE PACIFIC ON WEDNESDAY INTO THURSDAY
CARVES A MORE AMPLIFIED PATTERN...FAVORING BUILDING HEIGHTS AND
LOW-LEVEL SOUTHERLY FLOW TO INCREASE. GIVEN ALREADY ABOVE-NORMAL
TEMPERATURES UP TO CENTRAL ILLINOIS IN RECENT DAYS...THIS SYNOPTIC
PATTERN WILL FAVOR REPLENISHING AND ADDING TO THAT WARMTH AS WELL
AS SPREADING IT NORTH.
THE FRONTAL BOUNDARY IS LIKELY TO BREAK DOWN SOMEWHAT ON WEDNESDAY
AS JUST BROAD SOUTHERLY FLOW BEGINS. THIS FLOW WILL NOT BE STRONG
ENOUGH TO PREVENT LAKE COOLED AIR TO LIKELY REMAIN OVER NORTHEAST
ILLINOIS AND POSSIBLY EVEN FAR NORTHWEST INDIANA. APART FROM THE
MID 60S TO MID 70S IN THESE AREAS...LOWER TO POSSIBLY MID 80S ARE
EXPECTED ACROSS THE SOUTHERN AND FAR WESTERN FORECAST AREA.
THURSDAY WILL SEE SOUTH-SOUTHWEST WINDS INCREASE ENOUGH TO PREVENT
ANY LAKE COOLING. A THERMAL RIDGE DEFINED BY 925MB TEMPERATURES
OF 18C-19C AND 850MB TEMPERATURES OF 13-14C. USING REANALYSIS DATA
SINCE 1979...WHEN THESE WARM OF TEMPERATURES HAVE BEEN EXPERIENCED
IN THE FIRST HALF OF MAY IT YIELDS AN AVERAGE HIGH OF 83 DEGREES
AT CHICAGO OHARE. WITH SUNSHINE HIGHLY LIKELY ON THURSDAY GIVEN
THE AMPLIFIED FLOW KEEPING CIRRUS/DEBRIS AWAY ON MODEL
SOLUTIONS...HAVE BOOSTED TEMPERATURES TO THESE VALUES AND EVEN
SLIGHTLY HIGHER. SOME UPPER 80S ARE CERTAINLY POSSIBLE GIVEN THIS
PATTERN. THE RECORD HIGH FOR CHICAGO ON THURSDAY MAY 7TH IS 87
DEGREES SET IN 1964.
THE SECOND FOCUS ON THE LONG RANGE IS CONVECTIVE CHANCES. THE
POTENTIAL BEGINS FRIDAY WITH A NORTHERN STREAM FRONT EASING TOWARD
THE AREA...WHICH WILL COOL TEMPERATURES FOR SATURDAY AND POSSIBLY
SUNDAY TOO...ESPECIALLY FOR LAKE ADJACENT AREAS. AS THE UPPER-
LEVEL SOUTHWESTERLY FLOW INCREASES LATER IN THE WEEKEND...STORM
CHANCES WILL INCREASE AS HIGH PWAT AIR IS AGAIN FORECAST TO
ESTABLISH ITSELF ACROSS THE CORN BELT REGION. TIMING OF SHOWERS
AND STORMS LOOK TO AGAIN BE TIED TO MID-LEVEL IMPULSES WHICH CAN
OFTEN BE SUBTLE...WHICH DIMINISHES PREDICTABILITY AT THIS
POINT...SO CONTINUE WITH CHANCES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* EAST-NORTHEAST WINDS INCREASING BACK TO 10 KT THIS AFTERNOON.
* IFR CIGS POSSIBLY LIFTING TO MVFR THIS AFTERNOON...RETURNING TO
LIFR TONIGHT.
* SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM THIS AFTN...MAINLY
ALONG AND MORE LIKELY SOUTH OF MDW.
KMD
//DISCUSSION...UPDATED 12Z...
THE RAIN IS SLOWLY SHIFTING NORTHEAST AND WILL CLEAR THE REGION
THIS MORNING. NO ADDITIONAL LIGHTNING STRIKES ARE ANTICIPATED WITH
THESE SHOWERS. THERE ARE SCATTERED REPORTS OF MVFR CIGS AND THE
CIGS SHOULD LIFT TO VFR BEHIND THE SHOWERS. A STATIONARY FRONT
WILL REMAIN SOUTH OF THE TERMINALS TODAY AND COULD SEE SHOWERS AND
PERHAPS A THUNDERSTORM FIRE ALONG THE FRONT THIS AFTERNOON. THE
SHOWERS AND STORMS COULD IMPACT THE EASTERN TERMINALS...BUT DUE
TO LOW CONFIDENCE ONLY HAVE A VCSH. THINKING RFD WILL NOT BE
IMPACTED.
EAST WINDS AT 10 KT DIMINISH TO BELOW 10 KT THIS EVENING AND THEN
BEGIN TO BACK TO SOUTHEAST TOMORROW AS THE FRONT LIFTS NORTH.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM-HIGH THAT EAST-NORTHEAST WINDS PICK BACK UP TO AROUND 10
KT THIS AFTERNOON.
* MEDIUM-HIGH CONFIDENCE IN ORD REMAINING DRY THE REST OF THE
DAY. MEDIUM THAT AFTERNOON SHOWERS/ISOLATED T-STORMS REMAIN
SOUTH OF MDW.
* MEDIUM CONFIDENCE IN IFR CIGS LIFTING TO MVFR BUT LOW ON TIMING
AND DURATION. HIGH THAT IFR/LIFR CIGS AND VSBYS RETURN TONIGHT
BUT LOW ON TIMING.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...VFR. SOUTHEAST WINDS BCMG SOUTH.
THURSDAY...VFR. SOUTH WINDS.
FRIDAY...TSRA. MVFR CIGS PSBL OVERNIGHT. SOUTHWEST WINDS.
SATURDAY...SCHC TSRA DURING THE DAY AND CHC SHRA. NORTHWEST WINDS.
SUNDAY AND MONDAY...CHC TSRA. MVFR CIGS PSBL. NORTHEAST WINDS BCMG
SOUTHWEST MONDAY.
JEE
&&
.MARINE...
212 AM CDT
A STATIONARY FRONT IS OVER CENTRAL IL AND IT WILL REMAIN SOUTH OF
THE LAKE UNTIL IT LIFTS NORTH AS A WARM FRONT WEDNESDAY.
THEREFORE...NORTHEAST TO EAST WINDS WILL BECOME SOUTH WEDNESDAY
NIGHT BEHIND THE WARM FRONT. HIGH PRESSURE CURRENTLY OVER LAKE
SUPERIOR SHIFTS EAST OF LAKE MICHIGAN WEDNESDAY AND REMAINS OVER THE
EASTERN SEABOARD THROUGH THE WEEK. SOUTH WINDS UP TO 20 KT AT TIMES
ARE EXPECTED THROUGH FRIDAY. THE NEXT LOW FORMS OVER THE NORTHERN
ROCKIES WEDNESDAY AND MOVES OVER ONTARIO THURSDAY NIGHT AND FRIDAY.
THE LOWS COLD FRONT SWEEPS OVER THE LAKE SATURDAY AND WINDS BECOME
NORTH BEHIND THE FRONT.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
1045 AM CDT TUE MAY 5 2015
.UPDATE...
ISSUED AT 1045 AM CDT TUE MAY 5 2015
15Z/10AM SURFACE ANALYSIS SHOWS FRONTAL BOUNDARY EXTENDING FROM
NORTH-CENTRAL ILLINOIS INTO CENTRAL IOWA...GENERALLY ALONG A
KANKAKEE...TO PEORIA...TO DES MOINES LINE. WIDESPREAD RAIN
CONTINUES TO FALL NORTH OF THE FRONT: HOWEVER, MOSTLY SUNNY AND
DRY CONDITIONS PREVAIL TO THE SOUTH ACROSS CENTRAL ILLINOIS.
TEMPERATURES HAVE ALREADY RISEN WELL INTO THE 70S ACROSS ALL BUT
THE FAR NORTHERN KILX CWA. BASED ON THE 12Z UPPER AIR SOUNDING AND
ASSUMING MIXING UP TO ABOUT 750MB SIMILAR TO YESTERDAY
AFTERNOON...HIGHS TODAY SHOULD REACH THE LOWER TO MIDDLE 80S. HAVE
ADJUSTED TEMPS UP BY A FEW DEGREES ACCORDINGLY.
&&
.SHORT TERM...(TODAY)
ISSUED AT 332 AM CDT TUE MAY 5 2015
A FRONTAL BOUNDARY IS ORIENTED WEST-EAST ACROSS CENTRAL IL THIS
MORNING WITH PRECIPITATION IN ISENTROPIC ASCENT REGION LARGELY TO
THE NORTH OF THE BOUNDARY. MODELS INDICATE THE BOUNDARY AND
PRECIPITATION WILL SHIFT SLOWLY NORTHWARD TODAY. WEAK DISTURBANCES
MOVING ALONG THE BOUNDARY WILL PRODUCE SOME ENHANCEMENTS IN
CONVECTIVE SHOWER COVERAGE IN THE VICINITY...EARLY THIS MORNING FROM
AROUND THE ILLINOIS RIVER NORTHWESTWARD...AND LATE IN THE AFTERNOON
NORTH OF THE I-74 CORRIDOR. FOR THE MOST PART...CONVECTION SHOULD BE
WEAK AT THIS POINT WITH ONLY WEAK MID-LEVEL INSTABILITY REMAINING
THROUGH THE NIGHT...AND 0-6KM BULK SHEAR UP TO 25-30 KTS THIS
MORNING DIMINISHING SUBSTANTIALLY FOR THE AFTERNOON. 1000-1500
JOULES OF SURFACE-BASED CAPE SHOULD BE ABLE TO DEVELOP WITH
AFTERNOON HEATING ALONG/NORTH OF I-72 AND CAN`T RULE OUT ISOLATED
THUNDERSTORMS SOUTHWARD TO I-72 AS A RESULT.
.LONG TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 332 AM CDT TUE MAY 5 2015
ONGOING CONVECTION ALONG THE BOUNDARY OVER NORTHERN ILLINOIS THIS
MORNING NOT ONLY DRIVING THE WEATHER THROUGHOUT THE DAY, BUT INTO
THE OVERNIGHT AS WELL. GFS AND NAM CONTINUE TO KEEP A BIT OF PRECIP
PRETTY FAR SOUTH, AS FAR SOUTH AS A LINE FROM HAVANA TO BLOOMINGTON.
HOWEVER, THE RAP/RUC AND THE HRRR ARE PUSHING THE AREA OF CONVECTION
WELL TO THE NORTH THROUGH THE MORNING WITH THE BOUNDARY. WHEN THE
SECONDARY WAVE RIPPLES THROUGH THE REGION AFTER 00Z, IT WOULD BE
DISPLACED NORTH OF THE FA. THE 4KM WRF HAS JUST THAT SOLUTION,
STARTING MORE IN LINE WITH THE RAP/RUC AND HRRR...AND KEEPING THE FA
DRY AFTER 00Z, BUT A LITTLE MORE GENEROUS WITH SOME ISOLATED
INSTABILITY SHOWERS. HAVE KEPT ISO TS IN THE NORTH, MAINLY ALONG
AND NORTH OF I-74 FOR THE EARLY EVENING.
HIGH PRESSURE BEGINS TO BUILD BACK INTO THE REGION LATER TONIGHT,
SOUTHERLY WINDS PUSHING THE FRONT BACK TO THE NORTH AND OUT OF THE
FORECAST AREA THROUGH WED NIGHT. FORECAST REMAINS ROUGHLY THE SAME
BEYOND DAY 3... PRECIP CHANCES SLOWLY EDGING BACK INTO WEST CENTRAL
ILLINOIS FOR THURSDAY AS AN UPPER LEVEL WAVE PUSHES OUT OF THE SW.
THE ENERGY IS PART OF A GENERAL PATTERN SHIFT TO MORE SOUTHWESTERLY
FLOW WITH THE UPPER LEVEL TROF DIGGING BACK IN OVER THE SWRN CONUS.
THE SFC LOW MOVES OUT INTO THE UPPER MIDWEST AND INTO CANADA BY THE
END OF THE WEEK, BUT IN SHIFTING TO MORE SOUTHWESTERLY FLOW ALOFT,
OPENS THE DOOR TO A SERIES OF SHORTWAVES THAT KEEP THE FORECAST WET
FOR THE END OF THE WORK WEEK AND INTO THE WEEKEND. TEMPS RATHER
WARM THROUGH THE FORECAST WITH OVERCAST AND RAINY SKIES KEEPING THE
OVERNIGHT LOWS UP A BIT, BUT LIKELY NOT NEARLY AS WARM AS THE TREND
IN THE GUIDANCE. HAVE KNOCKED THEM DOWN A COUPLE DEGREES. SOUTHERLY
FLOW AND A RELATIVELY WARM AIRMASS KEEPING THE HIGHS A BIT ABOVE
NORMS, EVEN WITH THE PASSAGE OF THE FIRST LOW SKIRTING TO THE
NW...THE MID LEVELS REMAIN WARM UNTIL THE MAIN TROF OVER THE SW
LIFTS INTO AND OUT OF THE GREAT LAKES. COOLER AIR IN THE MIDLEVELS
IS ONLY AROUND FOR 36 HOURS DAY 7/8 BEFORE THE WARM AIRMASS
REESTABLISHES ITSELF.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 647 AM CDT TUE MAY 5 2015
SHOWERS HAVE MOVED OUT OF CENTRAL IL TAF SITES THIS MORNING WITH
VFR CONDITIONS AT MOST SITES...AREAS BKN060-080 CIGS...AND IFR-
LIFR CONDITIONS IN FOG AT SITES FROM KPIA-KC75 NORTHWESTWARD. FOG
WILL DISSIPATE WITH DAYTIME HEATING IN A FEW HOURS. ALSO WITH
DAYTIME HEATING...EXPECTING ISOLD TSRA DEVELOPING FROM AROUND
18Z-24Z. SCT-BKN CLOUD COVER SHOULD DEVELOP AS WELL GENERALLY
ABOVE MVFR THRESHOLDS. PROBABILITY OF DEVELOPMENT AND TIMING
UNCERTAINTY PREVENT EXPLICIT MENTION OF TSRA IN CENTRAL IL
TAFS...HOWEVER MVFR OR WORSE CIGS/VSBYS POSSIBLE IN ISOLATED
STORMS. INSTABILITY DECREASING OVERNIGHT SHOULD BRING AN END TO
ANY STORMS SHORTLY AFTER SUNSET.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARNES
SHORT TERM...ONTON
LONG TERM...HJS
AVIATION...ONTON
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1040 AM CDT TUE MAY 5 2015
.SHORT TERM...
329 AM CDT
THROUGH TONIGHT...
A LOOSELY-DEFINED AND NON-INTENSE MCS IS MOVING ACROSS NORTHERN
ILLINOIS DURING THE PREDAWN WITHIN A BROAD ZONE OF WARM ADVECTION.
RADAR MOSAIC AND VAD WIND PROFILER DATA INDICATE THE PRESENCE OF
A MID-LEVEL SHORT WAVE THAT LIKELY MAY BE CONVECTIVELY-ENHANCED
HELPING TO FOCUS THE BULK OF THE RAIN AND EMBEDDED THUNDER. BASED
ON RADAR TRENDS...HAVE GONE A LITTLE FURTHER SOUTH WITH RAIN AND
THUNDER CHANCES THROUGH 9 AM OR SO COMPARED TO THE SUITE OF HIGH-
RESOLUTION GUIDANCE. OVERALL EXPECT THE COVERAGE OF PRECIPITATION
TO CONSIDERABLY DIMINISH DURING THE MID TO LATE MORNING HOURS
WITH THE WAVE PASSING NORTHEAST. TRAILING SHOWERS AND A FEW
STORMS ARE LIKELY TO LINGER ALONG AND NORTH OF I-80 DURING THE
LATTER MORNING.
WHILE THE MID-LEVEL FLOW IS EXPECTED TO BECOME LESS DISTURBED BY
AFTERNOON PER WATER VAPOR ANALYSIS AND RAP AND NAM
FORECASTS...THE CHANCES FOR AFTERNOON CONVECTION LINGER IN THE
HIGH PWAT AIR /1.4 INCHES +/. THESE CHANCES WILL BE ATTACHED TO
OUTFLOWS/CONVERGENCE ZONES TRAILING THE MORNING SHORT WAVE AND
ITS CONVECTION...AS WELL AS THE SYNOPTIC CONVERGENCE ALONG THE
STATIONARY FRONT THAT EARLY THIS MORNING IS ROUGHLY NEAR I-74.
THIS FEATURE IS EXPECTED TO CREEP NORTHWARD THIS MORNING WITH THE
DECAY OF CONVECTION AND HEATING IN THE WARM SECTOR. THIS FRONT
WILL SEPARATE TEMPERATURES LIKELY AROUND 80 IN THE SOUTHERN
FORECAST AREA TO THE COOLER AND CLOUDY 60S IN NORTHEAST
ILLINOIS...WITH EVEN LOWER TO MID 50S ALONG THE LAKE SHORE. DEW
POINTS IN THE LOWER-MID 60S ALONG THE BOUNDARY WILL PROVIDE
MARGINAL BUT SOME MIXED LAYER INSTABILITY NEAR THE BOUNDARY THIS
AFTERNOON. CONVECTIVE ALLOWING MODELS GENERALLY SHOW DEVELOPMENT
THIS AFTERNOON BUT VARY WIDELY IN COVERAGE. WITH WEAK MID-LEVEL
FLOW AND BUILDING HEIGHTS NOT EXPECTING ANYTHING SEVERE AND HAVE
GONE WITH SCATTERED OR CHANCE WORDING DEPENDING ON THE AREA. THE
PRESENT MOST FAVORED FOCUS THIS AFTERNOON LOOKS TO BE ALONG I-80
AND JUST NORTH OF...BUT THAT COULD CERTAINLY SHIFT OR BE MORE
DIFFUSE...AND THE DAY SHIFT WILL BE ABLE TO BETTER ASSESS POST-
MORNING CONVECTIVE TRENDS.
MODELS AGREE ANY SHOWERS/STORMS THIS AFTERNOON WILL WANE IN THE
EVENING BEING MORE DIURNALLY DRIVEN. THE FRONTAL BOUNDARY WILL
LIKELY NOT MAKE TOO MUCH PROGRESS NORTH DURING THE
NIGHT...HANGING AROUND I-80 OR SO. THE HIGH ABSOLUTE MOISTURE
ALONG THE BOUNDARY COULD RESULT IN FOG ACROSS THE AREA...SOME OF
WHICH MAY BE DENSE AND LINGER INTO EARLY WEDNESDAY MORNING. HAVE
ADDED SOME GENERAL MENTION INTO THE FORECAST FOR THE TIME BEING.
MTF
&&
.LONG TERM...
329 AM CDT
WEDNESDAY NIGHT THROUGH MONDAY...
ATTENTION IN THE LONG RANGE IS FIRST ON THE IMPRESSIVE EARLY MAY
WARMTH THAT WILL MAKE IT FEEL LIKE SUMMER IN SOME PLACES WEDNESDAY
AND AREAWIDE THURSDAY AND POTENTIALLY FRIDAY TOO. THE UPPER JET
PATTERN COMING IN FROM THE PACIFIC ON WEDNESDAY INTO THURSDAY
CARVES A MORE AMPLIFIED PATTERN...FAVORING BUILDING HEIGHTS AND
LOW-LEVEL SOUTHERLY FLOW TO INCREASE. GIVEN ALREADY ABOVE-NORMAL
TEMPERATURES UP TO CENTRAL ILLINOIS IN RECENT DAYS...THIS SYNOPTIC
PATTERN WILL FAVOR REPLENISHING AND ADDING TO THAT WARMTH AS WELL
AS SPREADING IT NORTH.
THE FRONTAL BOUNDARY IS LIKELY TO BREAK DOWN SOMEWHAT ON WEDNESDAY
AS JUST BROAD SOUTHERLY FLOW BEGINS. THIS FLOW WILL NOT BE STRONG
ENOUGH TO PREVENT LAKE COOLED AIR TO LIKELY REMAIN OVER NORTHEAST
ILLINOIS AND POSSIBLY EVEN FAR NORTHWEST INDIANA. APART FROM THE
MID 60S TO MID 70S IN THESE AREAS...LOWER TO POSSIBLY MID 80S ARE
EXPECTED ACROSS THE SOUTHERN AND FAR WESTERN FORECAST AREA.
THURSDAY WILL SEE SOUTH-SOUTHWEST WINDS INCREASE ENOUGH TO PREVENT
ANY LAKE COOLING. A THERMAL RIDGE DEFINED BY 925MB TEMPERATURES
OF 18C-19C AND 850MB TEMPERATURES OF 13-14C. USING REANALYSIS DATA
SINCE 1979...WHEN THESE WARM OF TEMPERATURES HAVE BEEN EXPERIENCED
IN THE FIRST HALF OF MAY IT YIELDS AN AVERAGE HIGH OF 83 DEGREES
AT CHICAGO OHARE. WITH SUNSHINE HIGHLY LIKELY ON THURSDAY GIVEN
THE AMPLIFIED FLOW KEEPING CIRRUS/DEBRIS AWAY ON MODEL
SOLUTIONS...HAVE BOOSTED TEMPERATURES TO THESE VALUES AND EVEN
SLIGHTLY HIGHER. SOME UPPER 80S ARE CERTAINLY POSSIBLE GIVEN THIS
PATTERN. THE RECORD HIGH FOR CHICAGO ON THURSDAY MAY 7TH IS 87
DEGREES SET IN 1964.
THE SECOND FOCUS ON THE LONG RANGE IS CONVECTIVE CHANCES. THE
POTENTIAL BEGINS FRIDAY WITH A NORTHERN STREAM FRONT EASING TOWARD
THE AREA...WHICH WILL COOL TEMPERATURES FOR SATURDAY AND POSSIBLY
SUNDAY TOO...ESPECIALLY FOR LAKE ADJACENT AREAS. AS THE UPPER-
LEVEL SOUTHWESTERLY FLOW INCREASES LATER IN THE WEEKEND...STORM
CHANCES WILL INCREASE AS HIGH PWAT AIR IS AGAIN FORECAST TO
ESTABLISH ITSELF ACROSS THE CORN BELT REGION. TIMING OF SHOWERS
AND STORMS LOOK TO AGAIN BE TIED TO MID-LEVEL IMPULSES WHICH CAN
OFTEN BE SUBTLE...WHICH DIMINISHES PREDICTABILITY AT THIS
POINT...SO CONTINUE WITH CHANCES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* EAST-NORTHEAST WINDS INCREASING BACK TO 10 KT THIS AFTERNOON.
* IFR CIGS POSSIBLY LIFTING TO MVFR THIS AFTERNOON...RETURNING TO
LIFR TONIGHT.
* SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM THIS AFTN...MAINLY
ALONG AND MORE LIKELY SOUTH OF MDW.
KMD
//DISCUSSION...UPDATED 12Z...
THE RAIN IS SLOWLY SHIFTING NORTHEAST AND WILL CLEAR THE REGION
THIS MORNING. NO ADDITIONAL LIGHTNING STRIKES ARE ANTICIPATED WITH
THESE SHOWERS. THERE ARE SCATTERED REPORTS OF MVFR CIGS AND THE
CIGS SHOULD LIFT TO VFR BEHIND THE SHOWERS. A STATIONARY FRONT
WILL REMAIN SOUTH OF THE TERMINALS TODAY AND COULD SEE SHOWERS AND
PERHAPS A THUNDERSTORM FIRE ALONG THE FRONT THIS AFTERNOON. THE
SHOWERS AND STORMS COULD IMPACT THE EASTERN TERMINALS...BUT DUE
TO LOW CONFIDENCE ONLY HAVE A VCSH. THINKING RFD WILL NOT BE
IMPACTED.
EAST WINDS AT 10 KT DIMINISH TO BELOW 10 KT THIS EVENING AND THEN
BEGIN TO BACK TO SOUTHEAST TOMORROW AS THE FRONT LIFTS NORTH.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM-HIGH THAT EAST-NORTHEAST WINDS PICK BACK UP TO AROUND 10
KT THIS AFTERNOON.
* MEDIUM-HIGH CONFIDENCE IN ORD REMAINING DRY THE REST OF THE
DAY. MEDIUM THAT AFTERNOON SHOWERS/ISOLATED T-STORMS REMAIN
SOUTH OF MDW.
* MEDIUM CONFIDENCE IN IFR CIGS LIFTING TO MVFR BUT LOW ON TIMING
AND DURATION. HIGH THAT IFR/LIFR CIGS AND VSBYS RETURN TONIGHT
BUT LOW ON TIMING.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...VFR. SOUTHEAST WINDS BCMG SOUTH.
THURSDAY...VFR. SOUTH WINDS.
FRIDAY...TSRA. MVFR CIGS PSBL OVERNIGHT. SOUTHWEST WINDS.
SATURDAY...SCHC TSRA DURING THE DAY AND CHC SHRA. NORTHWEST WINDS.
SUNDAY AND MONDAY...CHC TSRA. MVFR CIGS PSBL. NORTHEAST WINDS BCMG
SOUTHWEST MONDAY.
JEE
&&
.MARINE...
212 AM CDT
A STATIONARY FRONT IS OVER CENTRAL IL AND IT WILL REMAIN SOUTH OF
THE LAKE UNTIL IT LIFTS NORTH AS A WARM FRONT WEDNESDAY.
THEREFORE...NORTHEAST TO EAST WINDS WILL BECOME SOUTH WEDNESDAY
NIGHT BEHIND THE WARM FRONT. HIGH PRESSURE CURRENTLY OVER LAKE
SUPERIOR SHIFTS EAST OF LAKE MICHIGAN WEDNESDAY AND REMAINS OVER THE
EASTERN SEABOARD THROUGH THE WEEK. SOUTH WINDS UP TO 20 KT AT TIMES
ARE EXPECTED THROUGH FRIDAY. THE NEXT LOW FORMS OVER THE NORTHERN
ROCKIES WEDNESDAY AND MOVES OVER ONTARIO THURSDAY NIGHT AND FRIDAY.
THE LOWS COLD FRONT SWEEPS OVER THE LAKE SATURDAY AND WINDS BECOME
NORTH BEHIND THE FRONT.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
903 AM CDT TUE MAY 5 2015
.SHORT TERM...
329 AM CDT
THROUGH TONIGHT...
A LOOSELY-DEFINED AND NON-INTENSE MCS IS MOVING ACROSS NORTHERN
ILLINOIS DURING THE PREDAWN WITHIN A BROAD ZONE OF WARM ADVECTION.
RADAR MOSAIC AND VAD WIND PROFILER DATA INDICATE THE PRESENCE OF
A MID-LEVEL SHORT WAVE THAT LIKELY MAY BE CONVECTIVELY-ENHANCED
HELPING TO FOCUS THE BULK OF THE RAIN AND EMBEDDED THUNDER. BASED
ON RADAR TRENDS...HAVE GONE A LITTLE FURTHER SOUTH WITH RAIN AND
THUNDER CHANCES THROUGH 9 AM OR SO COMPARED TO THE SUITE OF HIGH-
RESOLUTION GUIDANCE. OVERALL EXPECT THE COVERAGE OF PRECIPITATION
TO CONSIDERABLY DIMINISH DURING THE MID TO LATE MORNING HOURS
WITH THE WAVE PASSING NORTHEAST. TRAILING SHOWERS AND A FEW
STORMS ARE LIKELY TO LINGER ALONG AND NORTH OF I-80 DURING THE
LATTER MORNING.
WHILE THE MID-LEVEL FLOW IS EXPECTED TO BECOME LESS DISTURBED BY
AFTERNOON PER WATER VAPOR ANALYSIS AND RAP AND NAM
FORECASTS...THE CHANCES FOR AFTERNOON CONVECTION LINGER IN THE
HIGH PWAT AIR /1.4 INCHES +/. THESE CHANCES WILL BE ATTACHED TO
OUTFLOWS/CONVERGENCE ZONES TRAILING THE MORNING SHORT WAVE AND
ITS CONVECTION...AS WELL AS THE SYNOPTIC CONVERGENCE ALONG THE
STATIONARY FRONT THAT EARLY THIS MORNING IS ROUGHLY NEAR I-74.
THIS FEATURE IS EXPECTED TO CREEP NORTHWARD THIS MORNING WITH THE
DECAY OF CONVECTION AND HEATING IN THE WARM SECTOR. THIS FRONT
WILL SEPARATE TEMPERATURES LIKELY AROUND 80 IN THE SOUTHERN
FORECAST AREA TO THE COOLER AND CLOUDY 60S IN NORTHEAST
ILLINOIS...WITH EVEN LOWER TO MID 50S ALONG THE LAKE SHORE. DEW
POINTS IN THE LOWER-MID 60S ALONG THE BOUNDARY WILL PROVIDE
MARGINAL BUT SOME MIXED LAYER INSTABILITY NEAR THE BOUNDARY THIS
AFTERNOON. CONVECTIVE ALLOWING MODELS GENERALLY SHOW DEVELOPMENT
THIS AFTERNOON BUT VARY WIDELY IN COVERAGE. WITH WEAK MID-LEVEL
FLOW AND BUILDING HEIGHTS NOT EXPECTING ANYTHING SEVERE AND HAVE
GONE WITH SCATTERED OR CHANCE WORDING DEPENDING ON THE AREA. THE
PRESENT MOST FAVORED FOCUS THIS AFTERNOON LOOKS TO BE ALONG I-80
AND JUST NORTH OF...BUT THAT COULD CERTAINLY SHIFT OR BE MORE
DIFFUSE...AND THE DAY SHIFT WILL BE ABLE TO BETTER ASSESS POST-
MORNING CONVECTIVE TRENDS.
MODELS AGREE ANY SHOWERS/STORMS THIS AFTERNOON WILL WANE IN THE
EVENING BEING MORE DIURNALLY DRIVEN. THE FRONTAL BOUNDARY WILL
LIKELY NOT MAKE TOO MUCH PROGRESS NORTH DURING THE
NIGHT...HANGING AROUND I-80 OR SO. THE HIGH ABSOLUTE MOISTURE
ALONG THE BOUNDARY COULD RESULT IN FOG ACROSS THE AREA...SOME OF
WHICH MAY BE DENSE AND LINGER INTO EARLY WEDNESDAY MORNING. HAVE
ADDED SOME GENERAL MENTION INTO THE FORECAST FOR THE TIME BEING.
MTF
&&
.LONG TERM...
329 AM CDT
WEDNESDAY NIGHT THROUGH MONDAY...
ATTENTION IN THE LONG RANGE IS FIRST ON THE IMPRESSIVE EARLY MAY
WARMTH THAT WILL MAKE IT FEEL LIKE SUMMER IN SOME PLACES WEDNESDAY
AND AREAWIDE THURSDAY AND POTENTIALLY FRIDAY TOO. THE UPPER JET
PATTERN COMING IN FROM THE PACIFIC ON WEDNESDAY INTO THURSDAY
CARVES A MORE AMPLIFIED PATTERN...FAVORING BUILDING HEIGHTS AND
LOW-LEVEL SOUTHERLY FLOW TO INCREASE. GIVEN ALREADY ABOVE-NORMAL
TEMPERATURES UP TO CENTRAL ILLINOIS IN RECENT DAYS...THIS SYNOPTIC
PATTERN WILL FAVOR REPLENISHING AND ADDING TO THAT WARMTH AS WELL
AS SPREADING IT NORTH.
THE FRONTAL BOUNDARY IS LIKELY TO BREAK DOWN SOMEWHAT ON WEDNESDAY
AS JUST BROAD SOUTHERLY FLOW BEGINS. THIS FLOW WILL NOT BE STRONG
ENOUGH TO PREVENT LAKE COOLED AIR TO LIKELY REMAIN OVER NORTHEAST
ILLINOIS AND POSSIBLY EVEN FAR NORTHWEST INDIANA. APART FROM THE
MID 60S TO MID 70S IN THESE AREAS...LOWER TO POSSIBLY MID 80S ARE
EXPECTED ACROSS THE SOUTHERN AND FAR WESTERN FORECAST AREA.
THURSDAY WILL SEE SOUTH-SOUTHWEST WINDS INCREASE ENOUGH TO PREVENT
ANY LAKE COOLING. A THERMAL RIDGE DEFINED BY 925MB TEMPERATURES
OF 18C-19C AND 850MB TEMPERATURES OF 13-14C. USING REANALYSIS DATA
SINCE 1979...WHEN THESE WARM OF TEMPERATURES HAVE BEEN EXPERIENCED
IN THE FIRST HALF OF MAY IT YIELDS AN AVERAGE HIGH OF 83 DEGREES
AT CHICAGO OHARE. WITH SUNSHINE HIGHLY LIKELY ON THURSDAY GIVEN
THE AMPLIFIED FLOW KEEPING CIRRUS/DEBRIS AWAY ON MODEL
SOLUTIONS...HAVE BOOSTED TEMPERATURES TO THESE VALUES AND EVEN
SLIGHTLY HIGHER. SOME UPPER 80S ARE CERTAINLY POSSIBLE GIVEN THIS
PATTERN. THE RECORD HIGH FOR CHICAGO ON THURSDAY MAY 7TH IS 87
DEGREES SET IN 1964.
THE SECOND FOCUS ON THE LONG RANGE IS CONVECTIVE CHANCES. THE
POTENTIAL BEGINS FRIDAY WITH A NORTHERN STREAM FRONT EASING TOWARD
THE AREA...WHICH WILL COOL TEMPERATURES FOR SATURDAY AND POSSIBLY
SUNDAY TOO...ESPECIALLY FOR LAKE ADJACENT AREAS. AS THE UPPER-
LEVEL SOUTHWESTERLY FLOW INCREASES LATER IN THE WEEKEND...STORM
CHANCES WILL INCREASE AS HIGH PWAT AIR IS AGAIN FORECAST TO
ESTABLISH ITSELF ACROSS THE CORN BELT REGION. TIMING OF SHOWERS
AND STORMS LOOK TO AGAIN BE TIED TO MID-LEVEL IMPULSES WHICH CAN
OFTEN BE SUBTLE...WHICH DIMINISHES PREDICTABILITY AT THIS
POINT...SO CONTINUE WITH CHANCES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* SCATTERED RAIN SHOWERS SHIFT EAST OF THE TERMINALS OVER THE NEXT
COUPLE OF HOURS. ISOLATED THUNDER GENERALLY SOUTH OF MDW BUT
POSSIBLY IN THE 5-10 MILE RANGE.
* EAST WINDS 10-11 KT.
* IFR CIGS LIFTING TO MVFR
* SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM THIS AFTN.
KMD/JEE
//DISCUSSION...UPDATED 12Z...
THE RAIN IS SLOWLY SHIFTING NORTHEAST AND WILL CLEAR THE REGION
THIS MORNING. NO ADDITIONAL LIGHTNING STRIKES ARE ANTICIPATED WITH
THESE SHOWERS. THERE ARE SCATTERED REPORTS OF MVFR CIGS AND THE
CIGS SHOULD LIFT TO VFR BEHIND THE SHOWERS. A STATIONARY FRONT
WILL REMAIN SOUTH OF THE TERMINALS TODAY AND COULD SEE SHOWERS AND
PERHAPS A THUNDERSTORM FIRE ALONG THE FRONT THIS AFTERNOON. THE
SHOWERS AND STORMS COULD IMPACT THE EASTERN TERMINALS...BUT DUE
TO LOW CONFIDENCE ONLY HAVE A VCSH. THINKING RFD WILL NOT BE
IMPACTED.
EAST WINDS AT 10 KT DIMINISH TO BELOW 10 KT THIS EVENING AND THEN
BEGIN TO BACK TO SOUTHEAST TOMORROW AS THE FRONT LIFTS NORTH.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE IN SHOWERS...MEDIUM ON NO ADDITIONAL LIGHTNING
THIS MORNING EXCEPT ALONG AND SOUTH OF MDW.
* MEDIUM-LOW CONFIDENCE IN OCCURRENCE AND COVERAGE OF -SHRA THIS
AFTN. LOW CONFIDENCE IN OCCURRENCE AND COVERAGE OF TSRA.
* MEDIUM CONFIDENCE IN IFR CIGS LIFTING TO MVFR BUT LOW ON TIMING
AND DURATION.
KMD/JEE
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...VFR. SOUTHEAST WINDS BCMG SOUTH.
THURSDAY...VFR. SOUTH WINDS.
FRIDAY...TSRA. MVFR CIGS PSBL OVERNIGHT. SOUTHWEST WINDS.
SATURDAY...SCHC TSRA DURING THE DAY AND CHC SHRA. NORTHWEST WINDS.
SUNDAY AND MONDAY...CHC TSRA. MVFR CIGS PSBL. NORTHEAST WINDS BCMG
SOUTHWEST MONDAY.
JEE
&&
.MARINE...
212 AM CDT
A STATIONARY FRONT IS OVER CENTRAL IL AND IT WILL REMAIN SOUTH OF
THE LAKE UNTIL IT LIFTS NORTH AS A WARM FRONT WEDNESDAY.
THEREFORE...NORTHEAST TO EAST WINDS WILL BECOME SOUTH WEDNESDAY
NIGHT BEHIND THE WARM FRONT. HIGH PRESSURE CURRENTLY OVER LAKE
SUPERIOR SHIFTS EAST OF LAKE MICHIGAN WEDNESDAY AND REMAINS OVER THE
EASTERN SEABOARD THROUGH THE WEEK. SOUTH WINDS UP TO 20 KT AT TIMES
ARE EXPECTED THROUGH FRIDAY. THE NEXT LOW FORMS OVER THE NORTHERN
ROCKIES WEDNESDAY AND MOVES OVER ONTARIO THURSDAY NIGHT AND FRIDAY.
THE LOWS COLD FRONT SWEEPS OVER THE LAKE SATURDAY AND WINDS BECOME
NORTH BEHIND THE FRONT.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
648 AM CDT TUE MAY 5 2015
.SHORT TERM...
329 AM CDT
THROUGH TONIGHT...
A LOOSELY-DEFINED AND NON-INTENSE MCS IS MOVING ACROSS NORTHERN
ILLINOIS DURING THE PREDAWN WITHIN A BROAD ZONE OF WARM ADVECTION.
RADAR MOSAIC AND VAD WIND PROFILER DATA INDICATE THE PRESENCE OF
A MID-LEVEL SHORT WAVE THAT LIKELY MAY BE CONVECTIVELY-ENHANCED
HELPING TO FOCUS THE BULK OF THE RAIN AND EMBEDDED THUNDER. BASED
ON RADAR TRENDS...HAVE GONE A LITTLE FURTHER SOUTH WITH RAIN AND
THUNDER CHANCES THROUGH 9 AM OR SO COMPARED TO THE SUITE OF HIGH-
RESOLUTION GUIDANCE. OVERALL EXPECT THE COVERAGE OF PRECIPITATION
TO CONSIDERABLY DIMINISH DURING THE MID TO LATE MORNING HOURS
WITH THE WAVE PASSING NORTHEAST. TRAILING SHOWERS AND A FEW
STORMS ARE LIKELY TO LINGER ALONG AND NORTH OF I-80 DURING THE
LATTER MORNING.
WHILE THE MID-LEVEL FLOW IS EXPECTED TO BECOME LESS DISTURBED BY
AFTERNOON PER WATER VAPOR ANALYSIS AND RAP AND NAM
FORECASTS...THE CHANCES FOR AFTERNOON CONVECTION LINGER IN THE
HIGH PWAT AIR /1.4 INCHES +/. THESE CHANCES WILL BE ATTACHED TO
OUTFLOWS/CONVERGENCE ZONES TRAILING THE MORNING SHORT WAVE AND
ITS CONVECTION...AS WELL AS THE SYNOPTIC CONVERGENCE ALONG THE
STATIONARY FRONT THAT EARLY THIS MORNING IS ROUGHLY NEAR I-74.
THIS FEATURE IS EXPECTED TO CREEP NORTHWARD THIS MORNING WITH THE
DECAY OF CONVECTION AND HEATING IN THE WARM SECTOR. THIS FRONT
WILL SEPARATE TEMPERATURES LIKELY AROUND 80 IN THE SOUTHERN
FORECAST AREA TO THE COOLER AND CLOUDY 60S IN NORTHEAST
ILLINOIS...WITH EVEN LOWER TO MID 50S ALONG THE LAKE SHORE. DEW
POINTS IN THE LOWER-MID 60S ALONG THE BOUNDARY WILL PROVIDE
MARGINAL BUT SOME MIXED LAYER INSTABILITY NEAR THE BOUNDARY THIS
AFTERNOON. CONVECTIVE ALLOWING MODELS GENERALLY SHOW DEVELOPMENT
THIS AFTERNOON BUT VARY WIDELY IN COVERAGE. WITH WEAK MID-LEVEL
FLOW AND BUILDING HEIGHTS NOT EXPECTING ANYTHING SEVERE AND HAVE
GONE WITH SCATTERED OR CHANCE WORDING DEPENDING ON THE AREA. THE
PRESENT MOST FAVORED FOCUS THIS AFTERNOON LOOKS TO BE ALONG I-80
AND JUST NORTH OF...BUT THAT COULD CERTAINLY SHIFT OR BE MORE
DIFFUSE...AND THE DAY SHIFT WILL BE ABLE TO BETTER ASSESS POST-
MORNING CONVECTIVE TRENDS.
MODELS AGREE ANY SHOWERS/STORMS THIS AFTERNOON WILL WANE IN THE
EVENING BEING MORE DIURNALLY DRIVEN. THE FRONTAL BOUNDARY WILL
LIKELY NOT MAKE TOO MUCH PROGRESS NORTH DURING THE
NIGHT...HANGING AROUND I-80 OR SO. THE HIGH ABSOLUTE MOISTURE
ALONG THE BOUNDARY COULD RESULT IN FOG ACROSS THE AREA...SOME OF
WHICH MAY BE DENSE AND LINGER INTO EARLY WEDNESDAY MORNING. HAVE
ADDED SOME GENERAL MENTION INTO THE FORECAST FOR THE TIME BEING.
MTF
&&
.LONG TERM...
329 AM CDT
WEDNESDAY NIGHT THROUGH MONDAY...
ATTENTION IN THE LONG RANGE IS FIRST ON THE IMPRESSIVE EARLY MAY
WARMTH THAT WILL MAKE IT FEEL LIKE SUMMER IN SOME PLACES WEDNESDAY
AND AREAWIDE THURSDAY AND POTENTIALLY FRIDAY TOO. THE UPPER JET
PATTERN COMING IN FROM THE PACIFIC ON WEDNESDAY INTO THURSDAY
CARVES A MORE AMPLIFIED PATTERN...FAVORING BUILDING HEIGHTS AND
LOW-LEVEL SOUTHERLY FLOW TO INCREASE. GIVEN ALREADY ABOVE-NORMAL
TEMPERATURES UP TO CENTRAL ILLINOIS IN RECENT DAYS...THIS SYNOPTIC
PATTERN WILL FAVOR REPLENISHING AND ADDING TO THAT WARMTH AS WELL
AS SPREADING IT NORTH.
THE FRONTAL BOUNDARY IS LIKELY TO BREAK DOWN SOMEWHAT ON WEDNESDAY
AS JUST BROAD SOUTHERLY FLOW BEGINS. THIS FLOW WILL NOT BE STRONG
ENOUGH TO PREVENT LAKE COOLED AIR TO LIKELY REMAIN OVER NORTHEAST
ILLINOIS AND POSSIBLY EVEN FAR NORTHWEST INDIANA. APART FROM THE
MID 60S TO MID 70S IN THESE AREAS...LOWER TO POSSIBLY MID 80S ARE
EXPECTED ACROSS THE SOUTHERN AND FAR WESTERN FORECAST AREA.
THURSDAY WILL SEE SOUTH-SOUTHWEST WINDS INCREASE ENOUGH TO PREVENT
ANY LAKE COOLING. A THERMAL RIDGE DEFINED BY 925MB TEMPERATURES
OF 18C-19C AND 850MB TEMPERATURES OF 13-14C. USING REANALYSIS DATA
SINCE 1979...WHEN THESE WARM OF TEMPERATURES HAVE BEEN EXPERIENCED
IN THE FIRST HALF OF MAY IT YIELDS AN AVERAGE HIGH OF 83 DEGREES
AT CHICAGO OHARE. WITH SUNSHINE HIGHLY LIKELY ON THURSDAY GIVEN
THE AMPLIFIED FLOW KEEPING CIRRUS/DEBRIS AWAY ON MODEL
SOLUTIONS...HAVE BOOSTED TEMPERATURES TO THESE VALUES AND EVEN
SLIGHTLY HIGHER. SOME UPPER 80S ARE CERTAINLY POSSIBLE GIVEN THIS
PATTERN. THE RECORD HIGH FOR CHICAGO ON THURSDAY MAY 7TH IS 87
DEGREES SET IN 1964.
THE SECOND FOCUS ON THE LONG RANGE IS CONVECTIVE CHANCES. THE
POTENTIAL BEGINS FRIDAY WITH A NORTHERN STREAM FRONT EASING TOWARD
THE AREA...WHICH WILL COOL TEMPERATURES FOR SATURDAY AND POSSIBLY
SUNDAY TOO...ESPECIALLY FOR LAKE ADJACENT AREAS. AS THE UPPER-
LEVEL SOUTHWESTERLY FLOW INCREASES LATER IN THE WEEKEND...STORM
CHANCES WILL INCREASE AS HIGH PWAT AIR IS AGAIN FORECAST TO
ESTABLISH ITSELF ACROSS THE CORN BELT REGION. TIMING OF SHOWERS
AND STORMS LOOK TO AGAIN BE TIED TO MID-LEVEL IMPULSES WHICH CAN
OFTEN BE SUBTLE...WHICH DIMINISHES PREDICTABILITY AT THIS
POINT...SO CONTINUE WITH CHANCES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* RAIN SHIFTS EAST OF THE TERMINALS OVER THE NEXT COUPLE OF
HOURS.
* EAST WINDS 10-11 KT.
* MVFR CIGS LIFT TO VFR AFTER SHOWERS MOVE OUT THIS MORNING.
* SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM THIS AFTN.
JEE
//DISCUSSION...UPDATED 12Z...
THE RAIN IS SLOWLY SHIFTING NORTHEAST AND WILL CLEAR THE REGION
THIS MORNING. NO ADDITIONAL LIGHTNING STRIKES ARE ANTICIPATED WITH
THESE SHOWERS. THERE ARE SCATTERED REPORTS OF MVFR CIGS AND THE
CIGS SHOULD LIFT TO VFR BEHIND THE SHOWERS. A STATIONARY FRONT
WILL REMAIN SOUTH OF THE TERMINALS TODAY AND COULD SEE SHOWERS AND
PERHAPS A THUNDERSTORM FIRE ALONG THE FRONT THIS AFTERNOON. THE
SHOWERS AND STORMS COULD IMPACT THE EASTERN TERMINALS...BUT DUE
TO LOW CONFIDENCE ONLY HAVE A VCSH. THINKING RFD WILL NOT BE
IMPACTED.
EAST WINDS AT 10 KT DIMINISH TO BELOW 10 KT THIS EVENING AND THEN
BEGIN TO BACK TO SOUTHEAST TOMORROW AS THE FRONT LIFTS NORTH.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH CONFIDENCE IN SHOWERS AND NO ADDITIONAL LIGHTNING THIS
MORNING.
* MEDIUM-LOW CONFIDENCE IN OCCURRENCE AND COVERAGE OF -SHRA THIS
AFTN. LOW CONFIDENCE IN OCCURRENCE AND COVERAGE OF TSRA.
* MEDIUM-HIGH CONFIDENCE IN CIGS IMPROVING TO VFR THIS MORNING.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...VFR. SOUTHEAST WINDS BCMG SOUTH.
THURSDAY...VFR. SOUTH WINDS.
FRIDAY...TSRA. MVFR CIGS PSBL OVERNIGHT. SOUTHWEST WINDS.
SATURDAY...SCHC TSRA DURING THE DAY AND CHC SHRA. NORTHWEST WINDS.
SUNDAY AND MONDAY...CHC TSRA. MVFR CIGS PSBL. NORTHEAST WINDS BCMG
SOUTHWEST MONDAY.
JEE
&&
.MARINE...
212 AM CDT
A STATIONARY FRONT IS OVER CENTRAL IL AND IT WILL REMAIN SOUTH OF
THE LAKE UNTIL IT LIFTS NORTH AS A WARM FRONT WEDNESDAY.
THEREFORE...NORTHEAST TO EAST WINDS WILL BECOME SOUTH WEDNESDAY
NIGHT BEHIND THE WARM FRONT. HIGH PRESSURE CURRENTLY OVER LAKE
SUPERIOR SHIFTS EAST OF LAKE MICHIGAN WEDNESDAY AND REMAINS OVER THE
EASTERN SEABOARD THROUGH THE WEEK. SOUTH WINDS UP TO 20 KT AT TIMES
ARE EXPECTED THROUGH FRIDAY. THE NEXT LOW FORMS OVER THE NORTHERN
ROCKIES WEDNESDAY AND MOVES OVER ONTARIO THURSDAY NIGHT AND FRIDAY.
THE LOWS COLD FRONT SWEEPS OVER THE LAKE SATURDAY AND WINDS BECOME
NORTH BEHIND THE FRONT.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
647 AM CDT TUE MAY 5 2015
.SHORT TERM...(TODAY)
ISSUED AT 332 AM CDT TUE MAY 5 2015
A FRONTAL BOUNDARY IS ORIENTED WEST-EAST ACROSS CENTRAL IL THIS
MORNING WITH PRECIPITATION IN ISENTROPIC ASCENT REGION LARGELY TO
THE NORTH OF THE BOUNDARY. MODELS INDICATE THE BOUNDARY AND
PRECIPITATION WILL SHIFT SLOWLY NORTHWARD TODAY. WEAK DISTURBANCES
MOVING ALONG THE BOUNDARY WILL PRODUCE SOME ENHANCEMENTS IN
CONVECTIVE SHOWER COVERAGE IN THE VICINITY...EARLY THIS MORNING FROM
AROUND THE ILLINOIS RIVER NORTHWESTWARD...AND LATE IN THE AFTERNOON
NORTH OF THE I-74 CORRIDOR. FOR THE MOST PART...CONVECTION SHOULD BE
WEAK AT THIS POINT WITH ONLY WEAK MID-LEVEL INSTABILITY REMAINING
THROUGH THE NIGHT...AND 0-6KM BULK SHEAR UP TO 25-30 KTS THIS
MORNING DIMINISHING SUBSTANTIALLY FOR THE AFTERNOON. 1000-1500
JOULES OF SURFACE-BASED CAPE SHOULD BE ABLE TO DEVELOP WITH
AFTERNOON HEATING ALONG/NORTH OF I-72 AND CAN`T RULE OUT ISOLATED
THUNDERSTORMS SOUTHWARD TO I-72 AS A RESULT.
.LONG TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 332 AM CDT TUE MAY 5 2015
ONGOING CONVECTION ALONG THE BOUNDARY OVER NORTHERN ILLINOIS THIS
MORNING NOT ONLY DRIVING THE WEATHER THROUGHOUT THE DAY, BUT INTO
THE OVERNIGHT AS WELL. GFS AND NAM CONTINUE TO KEEP A BIT OF PRECIP
PRETTY FAR SOUTH, AS FAR SOUTH AS A LINE FROM HAVANA TO BLOOMINGTON.
HOWEVER, THE RAP/RUC AND THE HRRR ARE PUSHING THE AREA OF CONVECTION
WELL TO THE NORTH THROUGH THE MORNING WITH THE BOUNDARY. WHEN THE
SECONDARY WAVE RIPPLES THROUGH THE REGION AFTER 00Z, IT WOULD BE
DISPLACED NORTH OF THE FA. THE 4KM WRF HAS JUST THAT SOLUTION,
STARTING MORE IN LINE WITH THE RAP/RUC AND HRRR...AND KEEPING THE FA
DRY AFTER 00Z, BUT A LITTLE MORE GENEROUS WITH SOME ISOLATED
INSTABILITY SHOWERS. HAVE KEPT ISO TS IN THE NORTH, MAINLY ALONG
AND NORTH OF I-74 FOR THE EARLY EVENING.
HIGH PRESSURE BEGINS TO BUILD BACK INTO THE REGION LATER TONIGHT,
SOUTHERLY WINDS PUSHING THE FRONT BACK TO THE NORTH AND OUT OF THE
FORECAST AREA THROUGH WED NIGHT. FORECAST REMAINS ROUGHLY THE SAME
BEYOND DAY 3... PRECIP CHANCES SLOWLY EDGING BACK INTO WEST CENTRAL
ILLINOIS FOR THURSDAY AS AN UPPER LEVEL WAVE PUSHES OUT OF THE SW.
THE ENERGY IS PART OF A GENERAL PATTERN SHIFT TO MORE SOUTHWESTERLY
FLOW WITH THE UPPER LEVEL TROF DIGGING BACK IN OVER THE SWRN CONUS.
THE SFC LOW MOVES OUT INTO THE UPPER MIDWEST AND INTO CANADA BY THE
END OF THE WEEK, BUT IN SHIFTING TO MORE SOUTHWESTERLY FLOW ALOFT,
OPENS THE DOOR TO A SERIES OF SHORTWAVES THAT KEEP THE FORECAST WET
FOR THE END OF THE WORK WEEK AND INTO THE WEEKEND. TEMPS RATHER
WARM THROUGH THE FORECAST WITH OVERCAST AND RAINY SKIES KEEPING THE
OVERNIGHT LOWS UP A BIT, BUT LIKELY NOT NEARLY AS WARM AS THE TREND
IN THE GUIDANCE. HAVE KNOCKED THEM DOWN A COUPLE DEGREES. SOUTHERLY
FLOW AND A RELATIVELY WARM AIRMASS KEEPING THE HIGHS A BIT ABOVE
NORMS, EVEN WITH THE PASSAGE OF THE FIRST LOW SKIRTING TO THE
NW...THE MID LEVELS REMAIN WARM UNTIL THE MAIN TROF OVER THE SW
LIFTS INTO AND OUT OF THE GREAT LAKES. COOLER AIR IN THE MIDLEVELS
IS ONLY AROUND FOR 36 HOURS DAY 7/8 BEFORE THE WARM AIRMASS
REESTABLISHES ITSELF.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 647 AM CDT TUE MAY 5 2015
SHOWERS HAVE MOVED OUT OF CENTRAL IL TAF SITES THIS MORNING WITH
VFR CONDITIONS AT MOST SITES...AREAS BKN060-080 CIGS...AND IFR-
LIFR CONDITIONS IN FOG AT SITES FROM KPIA-KC75 NORTHWESTWARD. FOG
WILL DISSIPATE WITH DAYTIME HEATING IN A FEW HOURS. ALSO WITH
DAYTIME HEATING...EXPECTING ISOLD TSRA DEVELOPING FROM AROUND
18Z-24Z. SCT-BKN CLOUD COVER SHOULD DEVELOP AS WELL GENERALLY
ABOVE MVFR THRESHOLDS. PROBABILITY OF DEVELOPMENT AND TIMING
UNCERTAINTY PREVENT EXPLICIT MENTION OF TSRA IN CENTRAL IL
TAFS...HOWEVER MVFR OR WORSE CIGS/VSBYS POSSIBLE IN ISOLATED
STORMS. INSTABILITY DECREASING OVERNIGHT SHOULD BRING AN END TO
ANY STORMS SHORTLY AFTER SUNSET.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ONTON
LONG TERM...HJS
AVIATION...ONTON
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
400 AM CDT TUE MAY 5 2015
.SHORT TERM...
329 AM CDT
THROUGH TONIGHT...
A LOOSELY-DEFINED AND NON-INTENSE MCS IS MOVING ACROSS NORTHERN
ILLINOIS DURING THE PREDAWN WITHIN A BROAD ZONE OF WARM ADVECTION.
RADAR MOSAIC AND VAD WIND PROFILER DATA INDICATE THE PRESENCE OF
A MID-LEVEL SHORT WAVE THAT LIKELY MAY BE CONVECTIVELY-ENHANCED
HELPING TO FOCUS THE BULK OF THE RAIN AND EMBEDDED THUNDER. BASED
ON RADAR TRENDS...HAVE GONE A LITTLE FURTHER SOUTH WITH RAIN AND
THUNDER CHANCES THROUGH 9 AM OR SO COMPARED TO THE SUITE OF HIGH-
RESOLUTION GUIDANCE. OVERALL EXPECT THE COVERAGE OF PRECIPITATION
TO CONSIDERABLY DIMINISH DURING THE MID TO LATE MORNING HOURS
WITH THE WAVE PASSING NORTHEAST. TRAILING SHOWERS AND A FEW
STORMS ARE LIKELY TO LINGER ALONG AND NORTH OF I-80 DURING THE
LATTER MORNING.
WHILE THE MID-LEVEL FLOW IS EXPECTED TO BECOME LESS DISTURBED BY
AFTERNOON PER WATER VAPOR ANALYSIS AND RAP AND NAM
FORECASTS...THE CHANCES FOR AFTERNOON CONVECTION LINGER IN THE
HIGH PWAT AIR /1.4 INCHES +/. THESE CHANCES WILL BE ATTACHED TO
OUTFLOWS/CONVERGENCE ZONES TRAILING THE MORNING SHORT WAVE AND
ITS CONVECTION...AS WELL AS THE SYNOPTIC CONVERGENCE ALONG THE
STATIONARY FRONT THAT EARLY THIS MORNING IS ROUGHLY NEAR I-74.
THIS FEATURE IS EXPECTED TO CREEP NORTHWARD THIS MORNING WITH THE
DECAY OF CONVECTION AND HEATING IN THE WARM SECTOR. THIS FRONT
WILL SEPARATE TEMPERATURES LIKELY AROUND 80 IN THE SOUTHERN
FORECAST AREA TO THE COOLER AND CLOUDY 60S IN NORTHEAST
ILLINOIS...WITH EVEN LOWER TO MID 50S ALONG THE LAKE SHORE. DEW
POINTS IN THE LOWER-MID 60S ALONG THE BOUNDARY WILL PROVIDE
MARGINAL BUT SOME MIXED LAYER INSTABILITY NEAR THE BOUNDARY THIS
AFTERNOON. CONVECTIVE ALLOWING MODELS GENERALLY SHOW DEVELOPMENT
THIS AFTERNOON BUT VARY WIDELY IN COVERAGE. WITH WEAK MID-LEVEL
FLOW AND BUILDING HEIGHTS NOT EXPECTING ANYTHING SEVERE AND HAVE
GONE WITH SCATTERED OR CHANCE WORDING DEPENDING ON THE AREA. THE
PRESENT MOST FAVORED FOCUS THIS AFTERNOON LOOKS TO BE ALONG I-80
AND JUST NORTH OF...BUT THAT COULD CERTAINLY SHIFT OR BE MORE
DIFFUSE...AND THE DAY SHIFT WILL BE ABLE TO BETTER ASSESS POST-
MORNING CONVECTIVE TRENDS.
MODELS AGREE ANY SHOWERS/STORMS THIS AFTERNOON WILL WANE IN THE
EVENING BEING MORE DIURNALLY DRIVEN. THE FRONTAL BOUNDARY WILL
LIKELY NOT MAKE TOO MUCH PROGRESS NORTH DURING THE
NIGHT...HANGING AROUND I-80 OR SO. THE HIGH ABSOLUTE MOISTURE
ALONG THE BOUNDARY COULD RESULT IN FOG ACROSS THE AREA...SOME OF
WHICH MAY BE DENSE AND LINGER INTO EARLY WEDNESDAY MORNING. HAVE
ADDED SOME GENERAL MENTION INTO THE FORECAST FOR THE TIME BEING.
MTF
&&
.LONG TERM...
329 AM CDT
WEDNESDAY NIGHT THROUGH MONDAY...
ATTENTION IN THE LONG RANGE IS FIRST ON THE IMPRESSIVE EARLY MAY
WARMTH THAT WILL MAKE IT FEEL LIKE SUMMER IN SOME PLACES WEDNESDAY
AND AREAWIDE THURSDAY AND POTENTIALLY FRIDAY TOO. THE UPPER JET
PATTERN COMING IN FROM THE PACIFIC ON WEDNESDAY INTO THURSDAY
CARVES A MORE AMPLIFIED PATTERN...FAVORING BUILDING HEIGHTS AND
LOW-LEVEL SOUTHERLY FLOW TO INCREASE. GIVEN ALREADY ABOVE-NORMAL
TEMPERATURES UP TO CENTRAL ILLINOIS IN RECENT DAYS...THIS SYNOPTIC
PATTERN WILL FAVOR REPLENISHING AND ADDING TO THAT WARMTH AS WELL
AS SPREADING IT NORTH.
THE FRONTAL BOUNDARY IS LIKELY TO BREAK DOWN SOMEWHAT ON WEDNESDAY
AS JUST BROAD SOUTHERLY FLOW BEGINS. THIS FLOW WILL NOT BE STRONG
ENOUGH TO PREVENT LAKE COOLED AIR TO LIKELY REMAIN OVER NORTHEAST
ILLINOIS AND POSSIBLY EVEN FAR NORTHWEST INDIANA. APART FROM THE
MID 60S TO MID 70S IN THESE AREAS...LOWER TO POSSIBLY MID 80S ARE
EXPECTED ACROSS THE SOUTHERN AND FAR WESTERN FORECAST AREA.
THURSDAY WILL SEE SOUTH-SOUTHWEST WINDS INCREASE ENOUGH TO PREVENT
ANY LAKE COOLING. A THERMAL RIDGE DEFINED BY 925MB TEMPERATURES
OF 18C-19C AND 850MB TEMPERATURES OF 13-14C. USING REANALYSIS DATA
SINCE 1979...WHEN THESE WARM OF TEMPERATURES HAVE BEEN EXPERIENCED
IN THE FIRST HALF OF MAY IT YIELDS AN AVERAGE HIGH OF 83 DEGREES
AT CHICAGO OHARE. WITH SUNSHINE HIGHLY LIKELY ON THURSDAY GIVEN
THE AMPLIFIED FLOW KEEPING CIRRUS/DEBRIS AWAY ON MODEL
SOLUTIONS...HAVE BOOSTED TEMPERATURES TO THESE VALUES AND EVEN
SLIGHTLY HIGHER. SOME UPPER 80S ARE CERTAINLY POSSIBLE GIVEN THIS
PATTERN. THE RECORD HIGH FOR CHICAGO ON THURSDAY MAY 7TH IS 87
DEGREES SET IN 1964.
THE SECOND FOCUS ON THE LONG RANGE IS CONVECTIVE CHANCES. THE
POTENTIAL BEGINS FRIDAY WITH A NORTHERN STREAM FRONT EASING TOWARD
THE AREA...WHICH WILL COOL TEMPERATURES FOR SATURDAY AND POSSIBLY
SUNDAY TOO...ESPECIALLY FOR LAKE ADJACENT AREAS. AS THE UPPER-
LEVEL SOUTHWESTERLY FLOW INCREASES LATER IN THE WEEKEND...STORM
CHANCES WILL INCREASE AS HIGH PWAT AIR IS AGAIN FORECAST TO
ESTABLISH ITSELF ACROSS THE CORN BELT REGION. TIMING OF SHOWERS
AND STORMS LOOK TO AGAIN BE TIED TO MID-LEVEL IMPULSES WHICH CAN
OFTEN BE SUBTLE...WHICH DIMINISHES PREDICTABILITY AT THIS
POINT...SO CONTINUE WITH CHANCES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* RAIN CONTINUES THROUGH THE MORNING. A FEW CLAPS OF THUNDER ARE
NOT OUT OF THE QUESTION THROUGH DAYBREAK.
* EAST WINDS INCREASE TO 10-11 KT THIS MORNING AND AFTERNOON.
* IFR CIGS ARE EXPECTED BY 12Z AND NOT EXPECTING CIGS TO LIFT TO
MVFR UNTIL THIS EVENING IF NOT LATER.
* ANOTHER CHANCE OF SHOWERS AND PERHAPS A THUNDERSTORM THIS AFTN.
JEE
//DISCUSSION...UPDATED 06Z...
THE MESSY PATTERN CONTINUES. A SWATH OF SHOWERS AND A FEW
THUNDERSTORMS ARE SLOWLY PUSHING NORTHEAST AND WILL IMPACT ALL OF
THE TERMINALS. LIGHTNING STRIKES ARE FEW AND FAR BTWN SO KEPT
VCTS GOING THROUGH 12Z. IT IS STILL RATHER DRY OUT THERE DESPITE
THE RAIN...SO MVFR CIGS ARE ADVANCING SLOWLY. ALL GUIDANCE MEMBERS
INDICATE THE IFR CIGS TO OUR WEST WILL INFILTRATE THE TERMINALS
EARLY THIS MORNING. THE FRONT CURRENTLY OVER CENTRAL IL WILL
REMAIN SOUTH OF THE TERMINALS TODAY...WHICH SHOULD ME WE ARE
LOCKED INTO IFR CIGS UNTIL THE FRONT LIFTS NORTH WEDNESDAY
MORNING. WINDS WILL BE OUT OF THE EAST AS WELL.
GUIDANCE ALSO HINTS AT ANOTHER ROUND OF SHOWERS AND PERHAPS A
THUNDERSTORM THIS AFTERNOON SO PUT A PROB30 IN AS CONFIDENCE IS
NOT OVERLY HIGH GIVEN HOW MESSY THE PATTERN IS.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* HIGH CONFIDENCE IN SHOWERS THROUGH THIS MORNING AND ONLY A FEW
LIGHTNING STRIKES THROUGH DAYBREAK. MEDIUM-LOW CONFIDENCE IN
OCCURRENCE AND COVERAGE OF -SHRA AND TSRA THIS AFTN.
* MEDIUM-HIGH CONFIDENCE IN VSBY...STRONGER DOWNPOURS COULD LOWER
VSBY TO 2SM.
* MEDIUM-HIGH CONFIDENCE IN CIGS DROPPING TO IFR THIS MORNING.
MEDIUM CONFIDENCE IN CIGS LIFTING TO MVFR THIS EVENING AS THEY
COULD REMAIN IFR OVERNIGHT.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...SLIGHT CHANCE TSRA. MAINLY VFR. SOUTHEAST WINDS.
THURSDAY...VFR. SOUTH WINDS.
FRIDAY...CHANCE TSRA. MAINLY VFR. SOUTH WINDS.
SATURDAY...CHANCE OF TSRA WITH BRIEF MVFR...THOUGH MAINLY VFR.
SOUTHWEST WINDS BECOMING EAST-NORTHEAST.
SUNDAY...CHANCE OF TSRA. BRIEF MVFR POSSIBLE. SOUTHEAST WINDS.
RATZER
&&
.MARINE...
212 AM CDT
A STATIONARY FRONT IS OVER CENTRAL IL AND IT WILL REMAIN SOUTH OF
THE LAKE UNTIL IT LIFTS NORTH AS A WARM FRONT WEDNESDAY.
THEREFORE...NORTHEAST TO EAST WINDS WILL BECOME SOUTH WEDNESDAY
NIGHT BEHIND THE WARM FRONT. HIGH PRESSURE CURRENTLY OVER LAKE
SUPERIOR SHIFTS EAST OF LAKE MICHIGAN WEDNESDAY AND REMAINS OVER THE
EASTERN SEABOARD THROUGH THE WEEK. SOUTH WINDS UP TO 20 KT AT TIMES
ARE EXPECTED THROUGH FRIDAY. THE NEXT LOW FORMS OVER THE NORTHERN
ROCKIES WEDNESDAY AND MOVES OVER ONTARIO THURSDAY NIGHT AND FRIDAY.
THE LOWS COLD FRONT SWEEPS OVER THE LAKE SATURDAY AND WINDS BECOME
NORTH BEHIND THE FRONT.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
333 AM CDT TUE MAY 5 2015
.SHORT TERM...(TODAY)
ISSUED AT 332 AM CDT TUE MAY 5 2015
A FRONTAL BOUNDARY IS ORIENTED WEST-EAST ACROSS CENTRAL IL THIS
MORNING WITH PRECIPITATION IN ISENTROPIC ASCENT REGION LARGELY TO
THE NORTH OF THE BOUNDARY. MODELS INDICATE THE BOUNDARY AND
PRECIPITATION WILL SHIFT SLOWLY NORTHWARD TODAY. WEAK DISTURBANCES
MOVING ALONG THE BOUNDARY WILL PRODUCE SOME ENHANCEMENTS IN
CONVECTIVE SHOWER COVERAGE IN THE VICINITY...EARLY THIS MORNING FROM
AROUND THE ILLINOIS RIVER NORTHWESTWARD...AND LATE IN THE AFTERNOON
NORTH OF THE I-74 CORRIDOR. FOR THE MOST PART...CONVECTION SHOULD BE
WEAK AT THIS POINT WITH ONLY WEAK MID-LEVEL INSTABILITY REMAINING
THROUGH THE NIGHT...AND 0-6KM BULK SHEAR UP TO 25-30 KTS THIS
MORNING DIMINISHING SUBSTANTIALLY FOR THE AFTERNOON. 1000-1500
JOULES OF SURFACE-BASED CAPE SHOULD BE ABLE TO DEVELOP WITH
AFTERNOON HEATING ALONG/NORTH OF I-72 AND CAN`T RULE OUT ISOLATED
THUNDERSTORMS SOUTHWARD TO I-72 AS A RESULT.
&&
.LONG TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 332 AM CDT TUE MAY 5 2015
ONGOING CONVECTION ALONG THE BOUNDARY OVER NORTHERN ILLINOIS THIS
MORNING NOT ONLY DRIVING THE WEATHER THROUGHOUT THE DAY, BUT INTO
THE OVERNIGHT AS WELL. GFS AND NAM CONTINUE TO KEEP A BIT OF PRECIP
PRETTY FAR SOUTH, AS FAR SOUTH AS A LINE FROM HAVANA TO BLOOMINGTON.
HOWEVER, THE RAP/RUC AND THE HRRR ARE PUSHING THE AREA OF CONVECTION
WELL TO THE NORTH THROUGH THE MORNING WITH THE BOUNDARY. WHEN THE
SECONDARY WAVE RIPPLES THROUGH THE REGION AFTER 00Z, IT WOULD BE
DISPLACED NORTH OF THE FA. THE 4KM WRF HAS JUST THAT SOLUTION,
STARTING MORE IN LINE WITH THE RAP/RUC AND HRRR...AND KEEPING THE FA
DRY AFTER 00Z, BUT A LITTLE MORE GENEROUS WITH SOME ISOLATED
INSTABILITY SHOWERS. HAVE KEPT ISO TS IN THE NORTH, MAINLY ALONG
AND NORTH OF I-74 FOR THE EARLY EVENING.
HIGH PRESSURE BEGINS TO BUILD BACK INTO THE REGION LATER TONIGHT,
SOUTHERLY WINDS PUSHING THE FRONT BACK TO THE NORTH AND OUT OF THE
FORECAST AREA THROUGH WED NIGHT. FORECAST REMAINS ROUGHLY THE SAME
BEYOND DAY 3... PRECIP CHANCES SLOWLY EDGING BACK INTO WEST CENTRAL
ILLINOIS FOR THURSDAY AS AN UPPER LEVEL WAVE PUSHES OUT OF THE SW.
THE ENERGY IS PART OF A GENERAL PATTERN SHIFT TO MORE SOUTHWESTERLY
FLOW WITH THE UPPER LEVEL TROF DIGGING BACK IN OVER THE SWRN CONUS.
THE SFC LOW MOVES OUT INTO THE UPPER MIDWEST AND INTO CANADA BY THE
END OF THE WEEK, BUT IN SHIFTING TO MORE SOUTHWESTERLY FLOW ALOFT,
OPENS THE DOOR TO A SERIES OF SHORTWAVES THAT KEEP THE FORECAST WET
FOR THE END OF THE WORK WEEK AND INTO THE WEEKEND. TEMPS RATHER
WARM THROUGH THE FORECAST WITH OVERCAST AND RAINY SKIES KEEPING THE
OVERNIGHT LOWS UP A BIT, BUT LIKELY NOT NEARLY AS WARM AS THE TREND
IN THE GUIDANCE. HAVE KNOCKED THEM DOWN A COUPLE DEGREES. SOUTHERLY
FLOW AND A RELATIVELY WARM AIRMASS KEEPING THE HIGHS A BIT ABOVE
NORMS, EVEN WITH THE PASSAGE OF THE FIRST LOW SKIRTING TO THE
NW...THE MID LEVELS REMAIN WARM UNTIL THE MAIN TROF OVER THE SW
LIFTS INTO AND OUT OF THE GREAT LAKES. COOLER AIR IN THE MIDLEVELS
IS ONLY AROUND FOR 36 HOURS DAY 7/8 BEFORE THE WARM AIRMASS
REESTABLISHES ITSELF.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1144 PM CDT MON MAY 4 2015
FAIRLY SMALL AREA OF SHOWERS AND EMBEDDED THUNDERSTORMS IS STILL
MAKING ITS WAY ACROSS CENTRAL ILLINOIS, AND THIS AREA IS ONLY A
THREAT AT KBMI AND KCMI FOR A FEW MORE HOURS. MORE WIDESPREAD
SHOWERS/STORMS ARE UPSTREAM FROM THE CENTRAL ILLINOIS TERMINAL
AREA. RECENT SHORT RANGE/HIGH RESOLUTION MODEL GUIDANCE, SUPPORTED
BY RADAR LOOPS, SUGGESTS THAT MUCH OF THIS PRECIPITATION WILL PASS
TO THE NORTH OF THE LOCAL TERMINALS. KPIA AND KBMI STAND THE BEST
CHANCE OF BEING IMPACTED BY THIS UPSTREAM PRECIPITATION FOR
SEVERAL MORE HOURS, WHILE KSPI, KDEC, AND KCMI WILL BE MOSTLY DRY.
OUTSIDE OF ANY APPRECIABLE RAINFALL AREAS, WHICH WILL BRIEFLY
PRODUCE MVFR CONDITIONS, VFR CONDITIONS SHOULD PREVAIL. MOST OF
THE REST OF THE NIGHT SHOULD SEE VARIABLE WINDS WITH A NEARLY
STATIONARY BOUNDARY IN THE VICINITY. EXPECT WINDS TO TREND
SOUTHWESTERLY TUESDAY MORNING AS THE FRONT SHIFTS BACK NORTH.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ONTON
LONG TERM...HJS
AVIATION...BAK
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
332 AM CDT TUE MAY 5 2015
.SHORT TERM...
329 AM CDT
THROUGH TONIGHT...
A LOOSELY-DEFINED AND NON-INTENSE MCS IS MOVING ACROSS NORTHERN
ILLINOIS DURING THE PREDAWN WITHIN A BROAD ZONE OF WARM ADVECTION.
RADAR MOSAIC AND VAD WIND PROFILER DATA INDICATE THE PRESENCE OF
A MID-LEVEL SHORT WAVE THAT LIKELY MAY BE CONVECTIVELY-ENHANCED
HELPING TO FOCUS THE BULK OF THE RAIN AND EMBEDDED THUNDER. BASED
ON RADAR TRENDS...HAVE GONE A LITTLE FURTHER SOUTH WITH RAIN AND
THUNDER CHANCES THROUGH 9 AM OR SO COMPARED TO THE SUITE OF HIGH-
RESOLUTION GUIDANCE. OVERALL EXPECT THE COVERAGE OF PRECIPITATION
TO CONSIDERABLY DIMINISH DURING THE MID TO LATE MORNING HOURS
WITH THE WAVE PASSING NORTHEAST. TRAILING SHOWERS AND A FEW
STORMS ARE LIKELY TO LINGER ALONG AND NORTH OF I-80 DURING THE
LATTER MORNING.
WHILE THE MID-LEVEL FLOW IS EXPECTED TO BECOME LESS DISTURBED BY
AFTERNOON PER WATER VAPOR ANALYSIS AND RAP AND NAM
FORECASTS...THE CHANCES FOR AFTERNOON CONVECTION LINGER IN THE
HIGH PWAT AIR /1.4 INCHES +/. THESE CHANCES WILL BE ATTACHED TO
OUTFLOWS/CONVERGENCE ZONES TRAILING THE MORNING SHORT WAVE AND
ITS CONVECTION...AS WELL AS THE SYNOPTIC CONVERGENCE ALONG THE
STATIONARY FRONT THAT EARLY THIS MORNING IS ROUGHLY NEAR I-74.
THIS FEATURE IS EXPECTED TO CREEP NORTHWARD THIS MORNING WITH THE
DECAY OF CONVECTION AND HEATING IN THE WARM SECTOR. THIS FRONT
WILL SEPARATE TEMPERATURES LIKELY AROUND 80 IN THE SOUTHERN
FORECAST AREA TO THE COOLER AND CLOUDY 60S IN NORTHEAST
ILLINOIS...WITH EVEN LOWER TO MID 50S ALONG THE LAKE SHORE. DEW
POINTS IN THE LOWER-MID 60S ALONG THE BOUNDARY WILL PROVIDE
MARGINAL BUT SOME MIXED LAYER INSTABILITY NEAR THE BOUNDARY THIS
AFTERNOON. CONVECTIVE ALLOWING MODELS GENERALLY SHOW DEVELOPMENT
THIS AFTERNOON BUT VARY WIDELY IN COVERAGE. WITH WEAK MID-LEVEL
FLOW AND BUILDING HEIGHTS NOT EXPECTING ANYTHING SEVERE AND HAVE
GONE WITH SCATTERED OR CHANCE WORDING DEPENDING ON THE AREA. THE
PRESENT MOST FAVORED FOCUS THIS AFTERNOON LOOKS TO BE ALONG I-80
AND JUST NORTH OF...BUT THAT COULD CERTAINLY SHIFT OR BE MORE
DIFFUSE...AND THE DAY SHIFT WILL BE ABLE TO BETTER ASSESS POST-
MORNING CONVECTIVE TRENDS.
MODELS AGREE ANY SHOWERS/STORMS THIS AFTERNOON WILL WANE IN THE
EVENING BEING MORE DIURNALLY DRIVEN. THE FRONTAL BOUNDARY WILL
LIKELY NOT MAKE TOO MUCH PROGRESS NORTH DURING THE
NIGHT...HANGING AROUND I-80 OR SO. THE HIGH ABSOLUTE MOISTURE
ALONG THE BOUNDARY COULD RESULT IN FOG ACROSS THE AREA...SOME OF
WHICH MAY BE DENSE AND LINGER INTO EARLY WEDNESDAY MORNING. HAVE
ADDED SOME GENERAL MENTION INTO THE FORECAST FOR THE TIME BEING.
MTF
&&
.LONG TERM...
329 AM CDT
WEDNESDAY NIGHT THROUGH MONDAY...
ATTENTION IN THE LONG RANGE IS FIRST ON THE IMPRESSIVE EARLY MAY
WARMTH THAT WILL MAKE IT FEEL LIKE SUMMER IN SOME PLACES WEDNESDAY
AND AREAWIDE THURSDAY AND POTENTIALLY FRIDAY TOO. THE UPPER JET
PATTERN COMING IN FROM THE PACIFIC ON WEDNESDAY INTO THURSDAY
CARVES A MORE AMPLIFIED PATTERN...FAVORING BUILDING HEIGHTS AND
LOW-LEVEL SOUTHERLY FLOW TO INCREASE. GIVEN ALREADY ABOVE-NORMAL
TEMPERATURES UP TO CENTRAL ILLINOIS IN RECENT DAYS...THIS SYNOPTIC
PATTERN WILL FAVOR REPLENISHING AND ADDING TO THAT WARMTH AS WELL
AS SPREADING IT NORTH.
THE FRONTAL BOUNDARY IS LIKELY TO BREAK DOWN SOMEWHAT ON WEDNESDAY
AS JUST BROAD SOUTHERLY FLOW BEGINS. THIS FLOW WILL NOT BE STRONG
ENOUGH TO PREVENT LAKE COOLED AIR TO LIKELY REMAIN OVER NORTHEAST
ILLINOIS AND POSSIBLY EVEN FAR NORTHWEST INDIANA. APART FROM THE
MID 60S TO MID 70S IN THESE AREAS...LOWER TO POSSIBLY MID 80S ARE
EXPECTED ACROSS THE SOUTHERN AND FAR WESTERN FORECAST AREA.
THURSDAY WILL SEE SOUTH-SOUTHWEST WINDS INCREASE ENOUGH TO PREVENT
ANY LAKE COOLING. A THERMAL RIDGE DEFINED BY 925MB TEMPERATURES
OF 18C-19C AND 850MB TEMPERATURES OF 13-14C. USING REANALYSIS DATA
SINCE 1979...WHEN THESE WARM OF TEMPERATURES HAVE BEEN EXPERIENCED
IN THE FIRST HALF OF MAY IT YIELDS AN AVERAGE HIGH OF 83 DEGREES
AT CHICAGO OHARE. WITH SUNSHINE HIGHLY LIKELY ON THURSDAY GIVEN
THE AMPLIFIED FLOW KEEPING CIRRUS/DEBRIS AWAY ON MODEL
SOLUTIONS...HAVE BOOSTED TEMPERATURES TO THESE VALUES AND EVEN
SLIGHTLY HIGHER. SOME UPPER 80S ARE CERTAINLY POSSIBLE GIVEN THIS
PATTERN. THE RECORD HIGH FOR CHICAGO ON THURSDAY MAY 7TH IS 87
DEGREES SET IN 1964.
THE SECOND FOCUS ON THE LONG RANGE IS CONVECTIVE CHANCES. THE
POTENTIAL BEGINS FRIDAY WITH A NORTHERN STREAM FRONT EASING TOWARD
THE AREA...WHICH WILL COOL TEMPERATURES FOR SATURDAY AND POSSIBLY
SUNDAY TOO...ESPECIALLY FOR LAKE ADJACENT AREAS. AS THE UPPER-
LEVEL SOUTHWESTERLY FLOW INCREASES LATER IN THE WEEKEND...STORM
CHANCES WILL INCREASE AS HIGH PWAT AIR IS AGAIN FORECAST TO
ESTABLISH ITSELF ACROSS THE CORN BELT REGION. TIMING OF SHOWERS
AND STORMS LOOK TO AGAIN BE TIED TO MID-LEVEL IMPULSES WHICH CAN
OFTEN BE SUBTLE...WHICH DIMINISHES PREDICTABILITY AT THIS
POINT...SO CONTINUE WITH CHANCES.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* -SHRA IS MOVING IN AND WILL PERSIST THROUGH THE MORNING. A FEW
CLAPS OF THUNDER ARE NOT OUT OF THE QUESTION THROUGH DAYBREAK.
* EAST WINDS INCREASE TO 10-11 KT THIS MORNING AND AFTERNOON.
* IFR CIGS ARE EXPECTED BY 12Z AND NOT EXPECTING CIGS TO LIFT TO
MVFR UNTIL THIS EVENING IF NOT LATER.
* ANOTHER CHANCE OF SHOWERS AND PERHAPS A THUNDERSTORM THIS AFTN.
JEE
//DISCUSSION...UPDATED 06Z...
THE MESSY PATTERN CONTINUES. A SWATH OF SHOWERS AND A FEW
THUNDERSTORMS ARE SLOWLY PUSHING NORTHEAST AND WILL IMPACT ALL OF
THE TERMINALS. LIGHTNING STRIKES ARE FEW AND FAR BTWN SO KEPT
VCTS GOING THROUGH 12Z. IT IS STILL RATHER DRY OUT THERE DESPITE
THE RAIN...SO MVFR CIGS ARE ADVANCING SLOWLY. ALL GUIDANCE MEMBERS
INDICATE THE IFR CIGS TO OUR WEST WILL INFILTRATE THE TERMINALS
EARLY THIS MORNING. THE FRONT CURRENTLY OVER CENTRAL IL WILL
REMAIN SOUTH OF THE TERMINALS TODAY...WHICH SHOULD ME WE ARE
LOCKED INTO IFR CIGS UNTIL THE FRONT LIFTS NORTH WEDNESDAY
MORNING. WINDS WILL BE OUT OF THE EAST AS WELL.
GUIDANCE ALSO HINTS AT ANOTHER ROUND OF SHOWERS AND PERHAPS A
THUNDERSTORM THIS AFTERNOON SO PUT A PROB30 IN AS CONFIDENCE IS
NOT OVERLY HIGH GIVEN HOW MESSY THE PATTERN IS.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN SHOWERS THROUGH THIS MORNING AND ONLY A FEW
LIGHTNING STRIKES THROUGH DAYBREAK. MEDIUM-LOW CONFIDENCE IN
OCCURRENCE AND COVERAGE OF -SHRA AND TSRA THIS AFTN.
* MEDIUM-HIGH CONFIDENCE IN VSBY...STRONGER DOWNPOURS COULD LOWER
CIGS TO 2SM.
* MEDIUM-HIGH CONFIDENCE IN CIGS DROPPING TO IFR THIS MORNING.
MEDIUM CONFIDENCE IN CIGS LIFTING TO MVFR THIS EVENING AS THEY
COULD REMAIN IFR OVERNIGHT.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...SLIGHT CHANCE TSRA. MAINLY VFR. SOUTHEAST WINDS.
THURSDAY...VFR. SOUTH WINDS.
FRIDAY...CHANCE TSRA. MAINLY VFR. SOUTH WINDS.
SATURDAY...CHANCE OF TSRA WITH BRIEF MVFR...THOUGH MAINLY VFR.
SOUTHWEST WINDS BECOMING EAST-NORTHEAST.
SUNDAY...CHANCE OF TSRA. BRIEF MVFR POSSIBLE. SOUTHEAST WINDS.
RATZER
&&
.MARINE...
212 AM CDT
A STATIONARY FRONT IS OVER CENTRAL IL AND IT WILL REMAIN SOUTH OF
THE LAKE UNTIL IT LIFTS NORTH AS A WARM FRONT WEDNESDAY.
THEREFORE...NORTHEAST TO EAST WINDS WILL BECOME SOUTH WEDNESDAY
NIGHT BEHIND THE WARM FRONT. HIGH PRESSURE CURRENTLY OVER LAKE
SUPERIOR SHIFTS EAST OF LAKE MICHIGAN WEDNESDAY AND REMAINS OVER THE
EASTERN SEABOARD THROUGH THE WEEK. SOUTH WINDS UP TO 20 KT AT TIMES
ARE EXPECTED THROUGH FRIDAY. THE NEXT LOW FORMS OVER THE NORTHERN
ROCKIES WEDNESDAY AND MOVES OVER ONTARIO THURSDAY NIGHT AND FRIDAY.
THE LOWS COLD FRONT SWEEPS OVER THE LAKE SATURDAY AND WINDS BECOME
NORTH BEHIND THE FRONT.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
1151 PM CDT MON MAY 4 2015
.UPDATE...
ISSUED AT 848 PM CDT MON MAY 4 2015
LATEST SURFACE ANALYSIS HAS A NEARLY STATIONARY FRONTAL BOUNDARY
CUTTING WEST TO EAST ACROSS CENTRAL ILLINOIS ROUGHLY FROM QUINCY
TO PARIS. THIS BOUNDARY IS FAIRLY WELL DELINEATED BY AN EXPANDING
FINE LINE OF SHOWERS AND ISOLATED THUNDERSTORMS. THE PREVIOUS
INTENSITY OF THE AREA OF STORMS PUSHING INTO WEST-CENTRAL ILLINOIS
HAS FADED WITH THE LOSS OF DIURNAL INSTABILITY WITH THE BULK OF
THE STORMS IN OUR VICINITY CURRENTLY OF THE "GARDEN VARIETY".
THE BULK OF THE GUIDANCE, ESPECIALLY RECENT RUNS OF MANY HIGH
RESOLUTION MODELS, SUGGEST THE BULK OF THE SHOWERS/STORMS THOUGH
THE NIGHT WILL EXIST ALONG/NORTH OF THE FRONTAL BOUNDARY. ALSO, A
WAVE LIFTING NORTHEAST OUT OF THE PLAINS IS EXPECTED TO HELP PUSH
THE FRONT A LITTLE FURTHER NORTH WITH TIME OVERNIGHT. THESE
FACTORS WOULD SUGGEST THE BULK OF THE UPSTREAM PRECIPITATION OVER
IOWA AND MISSOURI WOULD TRACK NORTH OF MOST OF THE FORECAST AREA.
PLAN TO UPDATE FORECAST TO REFINE POPS, MAINLY TO PUSH THE RISK
FURTHER NORTH. OTHERWISE, MINOR TWEAKS ARE NEEDED FOR THE LATEST
HOURLY TRENDS.
&&
.SHORT TERM...(TONIGHT)
ISSUED AT 245 PM CDT MON MAY 4 2015
FRONTAL BOUNDARY EXTENDING FROM SOUTHERN LAKE MICHIGAN TO NORTHERN
KANSAS WILL SINK SOUTHWARD...EVENTUALLY STALLING NEAR THE I-72
CORRIDOR LATER THIS EVENING. SHOWERS AND THUNDERSTORMS WILL DEVELOP
ALONG THE BOUNDARY...WITH MOST MODEL SOLUTIONS SUGGESTING THE
GREATEST AREAL COVERAGE OF PRECIP ACROSS THE NORTHERN HALF OF THE
KILX CWA. HRRR IS SHOWING WIDELY SCATTERED STORMS DEVELOPING OVER
THE NEXT COUPLE OF HOURS...WITH THE CONVECTION BECOMING MORE
WIDESPREAD AFTER SUNSET AS A WEAK LOW-LEVEL JET DEVELOPS. HAVE
ADJUSTED RAIN CHANCES ACCORDINGLY...WITH LIKELY POPS ALONG/NORTH OF
I-72 TAPERING DOWN TO JUST SLIGHT CHANCE ALONG/SOUTH OF I-70.
.LONG TERM...(TUESDAY THROUGH MONDAY)
ISSUED AT 245 PM CDT MON MAY 4 2015
AN UPPER LEVEL RIDGE IS EXPECTED TO AMPLIFY OVER THE CENTER OF THE
NATION STARTING ON TUESDAY WHICH SHOULD PUSH THE BETTER CHANCES FOR
SHOWERS AND THUNDERSTORMS NORTH OF THE FORECAST AREA...AT LEAST INTO
THURSDAY. SHORTWAVE ENERGY IS THEN FORECAST TO EJECTS NORTH OUT OF
THE SOUTHERN PLAINS AND BRING ABOUT A CHANCE FOR MORE SHOWERS AND
THUNDERSTORMS...ESPECIALLY ACROSS OUR WEST...THURSDAY NIGHT INTO
FRIDAY. A MORE POTENT 500 MB TROF IS THEN FORECAST TO SLOWLY TRACK
OUT OF THE ROCKIES DURING THE WEEKEND BRINGING PERIODS OF SHOWERS
AND THUNDERSTORMS TO THE FORECAST AREA. MOST MODELS TRACK THIS LOW
NORTH-NORTHEAST ON SUNDAY SUGGESTING THE MORE SIGNIFICANT LIFT TO
REMAIN WEST OF OUR AREA UNTIL LATE SUNDAY OR MONDAY OF NEXT WEEK
WHEN THE SYSTEM WILL SWING A COLD FRONT THROUGH CENTRAL ILLINOIS.
UNTIL THEN...WARM TEMPERATURES TO PREVAIL WITH THE SHOWER AND STORM
CHANCES ACROSS THE FAR NORTH TOMORROW AS THE FRONT RETREATS BACK
TO THE NORTH...AND THEN RAIN CHANCES RETURN LATE THU INTO FRIDAY
AND HOLDS THROUGH EARLY NEXT WEEK BEFORE WE FINALLY GET A CHANGE
IN AIR MASS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1144 PM CDT MON MAY 4 2015
FAIRLY SMALL AREA OF SHOWERS AND EMBEDDED THUNDERSTORMS IS STILL
MAKING ITS WAY ACROSS CENTRAL ILLINOIS, AND THIS AREA IS ONLY A
THREAT AT KBMI AND KCMI FOR A FEW MORE HOURS. MORE WIDESPREAD
SHOWERS/STORMS ARE UPSTREAM FROM THE CENTRAL ILLINOIS TERMINAL
AREA. RECENT SHORT RANGE/HIGH RESOLUTION MODEL GUIDANCE, SUPPORTED
BY RADAR LOOPS, SUGGESTS THAT MUCH OF THIS PRECIPITATION WILL PASS
TO THE NORTH OF THE LOCAL TERMINALS. KPIA AND KBMI STAND THE BEST
CHANCE OF BEING IMPACTED BY THIS UPSTREAM PRECIPITATION FOR
SEVERAL MORE HOURS, WHILE KSPI, KDEC, AND KCMI WILL BE MOSTLY DRY.
OUTSIDE OF ANY APPRECIABLE RAINFALL AREAS, WHICH WILL BRIEFLY
PRODUCE MVFR CONDITIONS, VFR CONDTIONS SHOULD PREVAIL. MOST OF THE
REST OF THE NIGHT SHOULD SEE VARIABLE WINDS WITH A NEARLY
STATIONARY BOUNDARY IN THE VICINITY. EXPECT WINDS TO TREND
SOUTHWESTERLY TUESDAY MORNING AS THE FRONT SHIFTS BACK NORTH.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BAK
SHORT TERM...BARNES
LONG TERM...SMITH
AVIATION...BAK
AREA FORECAST DISCUSSION
NWS DES MOINES IA
330 PM CDT TUE MAY 5 2015
.SHORT TERM /TONIGHT/...
ISSUED AT 330 PM CDT TUE MAY 5 2015
THE FRONTAL BOUNDARY REMAINS DRAPED ACROSS CENTRAL IOWA AND HAS NOT
MOVED MUCH AT ALL TODAY. IT MADE A VERY SLOW PROGRESSION NORTHWARD
AND CURRENTLY SITS JUST SOUTH OF HIGHWAY 20...VERSUS INTERSTATE 80
THIS MORNING. PRECIPITATION FROM EARLIER THIS MORNING FADED AS IT
TREKKED NORTHWARD AND AWAY FROM WHAT LITTLE LIFT...MAINLY WAA
OVER THE BOUNDARY...REMAINED. CLOUD COVER THAT LINGERED WELL INTO
THIS AFTERNOON ACROSS SOUTHERN IOWA PREVENTED SBCAPE VALUES FROM
SOARING...BUT HAVE REBOUNDED TO 1500-2000 J/KG WITH NIL CIN ACROSS
CENTRAL AND SOUTHERN IOWA. AREAS THAT SAW SUNSHINE WILL LIKELY
REACH THEIR CONVECTIVE TEMPS...GENERALLY IN THE UPPER 70S...AND IS
BEING REALIZED NOW AS SOME WEAK CONVECTION IS CURRENTLY FIRING UP
IN SOUTH CENTRAL IOWA AND WEST OF FORT DODGE. WEAK
SHEAR...GENERALLY 20KTS OR LESS...AND NO CAP WILL RESULT IN
NUMEROUS PULSE STORMS THAT WILL LIMIT SEVERE POTENTIAL AS THEY
FIGHT FOR ENERGY. THE HRRR APPEARS TO HAVE THE BEST HANDLE ON THE
SITUATION ON CURRENT CONVECTION AND HAS ALL OF IT GONE BY 03Z WITH
THE LACK OF ANY SIGNIFICANT LIFTING MECHANISM OVER NIGHT.
TEMPERATURES STRUGGLED TO REACH DAYTIME HIGHS WITH THICK...AND
GENERALLY LOW...CLOUDS OVER MUCH OF NORTHERN IOWA. AS A RESULT MANY
LOCATIONS STILL SIT IN THE UPPER 50S. WITH THAT IN MIND...HAVE
DROPPED LOWS ONLY A COUPLE OF DEGREES SINCE DEWPOINTS WILL REMAIN
FAIRLY HIGH AND STOP ANY CRASHING TEMPS. FOG MAY BE OF CONCERN
ACROSS THE NORTH AS WELL...BUT MAY BE LIMITED WITH WINDS AROUND
10KTS. SITES THAT SEE WINDS DROP A BIT MAY SEE PERIODS OF FOG.
.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
ISSUED AT 330 PM CDT TUE MAY 5 2015
GENERALLY SOUTHWESTERLY 500 MB FLOW ACROSS IOWA AND THE MIDWEST
WILL RESULT IN AN ACTIVE AND FAIRLY WET WEATHER PATTERN THROUGH
THE WEEKEND. THIS PATTERN WILL BE PUNCTUATED BY TWO FAIRLY ROBUST
LOW PRESSURE SYSTEMS AND AN INTERMEDIARY PERIOD OF SUBTLE
SHORTWAVES MOVING THROUGH THE AFOREMENTIONED SOUTHWESTERLY FLOW.
THE FIRST BIG SYSTEM IS CURRENTLY TRACKING ACROSS THE SOUTHERN
ROCKIES IN THE FORM OF A DEEP OPEN WAVE...AND WILL MOVE UP OVER
OUR REGION ON WEDNESDAY AND WEDNESDAY NIGHT. MEANWHILE A LARGE
CLOSED 500 MB LOW CURRENTLY MOVING ASHORE OVER WASHINGTON/BRITISH
COLUMBIA WILL DIVE SOUTHWARD ALONG THE PACIFIC U.S.
COAST...REACHING NORTHERN CALIFORNIA BY LATE WEDNESDAY NIGHT.
THEREAFTER...AS THE FIRST SYSTEM DEPARTS QUICKLY TO OUR NORTHEAST
AND THE SECOND SYSTEM DIGS IN AND DEEPENS OVER THE SOUTHWEST U.S.
IT WILL MAINTAIN SOUTHWESTERLY FLOW OVER IOWA...THROUGH WHICH
SUBTLE SHORTWAVES WILL MOVE AT THE END OF THIS WEEK. FINALLY...THE
LARGE SOUTHWEST U.S. LOW WILL EJECT UP ACROSS THE MIDWEST SOMETIME
AROUND SUNDAY.
AS THE LEADING LOW PRESSURE TROUGH MOVES UP INTO THE REGION ON
WEDNESDAY IT WILL PUSH A LARGE REGION OF WARM AIR AND THETA E
ADVECTION UP ACROSS IOWA. WITHIN THIS REGION WIDESPREAD
THUNDERSTORMS SHOULD DEVELOP OVER NEBRASKA AND KANSAS
TONIGHT...THEN SLOWLY FADE AS THEY TRANSLATE ACROSS OUR FORECAST
AREA DURING THE DAY WEDNESDAY. WILL MAINTAIN LIKELY POPS FOR MOST
OF THE DAY...HOWEVER...CONFIDENCE BY WEDNESDAY AFTERNOON IS NOT
HIGH AS IT APPEARS THAT IN WAKE OF THE INITIAL BAND OF WARM AIR
ADVECTION THERE MAY BE LITTLE TO FORCE TRAILING CONVECTION AND WE
COULD SEE A LULL SIMILAR TO TODAY. IN ANY EVENT...WHILE THERE IS
SOME MARGINAL INSTABILITY AND DECENT DEEP LAYER SHEAR...NEARLY
UNIFORM LOW LEVEL WINDS AND A LACK OF ANY KIND OF FOCUS MECHANISM
LEAD TO A LOW RISK OF SEVERE WEATHER WHICH IS WELL OUTLINED BY
SPC. ON WEDNESDAY NIGHT ANOTHER EXPANSION OF THUNDERSTORM COVERAGE
WILL LIKELY OCCUR WITH THE NOCTURNAL LOW LEVEL JET ON THE EASTERN
FLANK OF THE UPPER LOW PRESSURE SYSTEM...BUT THIS ACTIVITY WILL
MOSTLY BE TO OUR WEST ACROSS NEBRASKA...SOUTH DAKOTA AND
NORTHWESTERN IOWA AND ONCE AGAIN WITH A LOW SEVERE WEATHER THREAT
IN OUR AREA. FORECAST POPS HAVE BEEN TRENDED TOWARD THIS DIRECTION
AND TIMING.
POTENTIALLY THE MOST ACTIVE PERIOD FOR OUR AREA WILL COME ON
THURSDAY. IT APPEARS THAT ONE OR TWO SHORTWAVES MOVING OVERHEAD
WILL PUSH A SYNOPTIC SURFACE TROUGH SLOWLY ACROSS OUR AREA ON
THURSDAY NIGHT. AHEAD OF THIS TROUGH...AT PEAK HEATING TIME LATE
THURSDAY AFTERNOON AND EVENING PROGNOSTIC MODELS UNANIMOUSLY
DEPICT A SWATH OF STRONG INSTABILITY DEVELOPING AHEAD OF THE
BOUNDARY...THOUGH THIS COULD BE TEMPERED BY DEBRIS FROM EARLY
MORNING CONVECTION. WHILE UPPER LEVEL FORCING IS SOMEWHAT LESS
IMPRESSIVE DURING THIS TIME...DEEP SHEAR IN THE 25 TO 35 KT RANGE
COUPLED WITH SURFACE CAPE APPROACHING 3000 J/KG WOULD CERTAINLY
INDICATE A SEVERE WEATHER THREAT. THIS WILL BEAR WATCHING AS WE
PROGRESS THROUGH THE WORK WEEK.
THE FORECAST FROM LATE THURSDAY NIGHT THROUGH SATURDAY IS
DEPENDENT ON HOW FAR SOUTHEAST THE ABOVE DISCUSSED SURFACE TROUGH
CAN PROGRESS. IT WILL LIKELY STALL SOMEWHERE OVER SOUTHEASTERN
IOWA OR MISSOURI/ILLINOIS...WITH SUBSEQUENT SHORTWAVES MOVING
OVERHEAD AND KICKING OFF ONE OR MORE ROUNDS OF THUNDERSTORMS ALONG
AND NORTHWEST OF THE FRONTAL ZONE. HOWEVER...IT IS UNCLEAR HOW FAR
SOUTHEAST OF OUR AREA THE BOUNDARY WILL LIE AND THUS HOW FAR INTO
OUR AREA THESE STORMS MAY PENETRATE. THERE IS LITTLE TO NO MODEL
CONSISTENCY IN THIS AREA...AND FOR NOW HAVE STUCK TO CHANCE POPS
ACROSS OUR SOUTHEASTERN AREAS DEPICTING A ROUGH CONSENSUS
APPROACH. IN ANY EVENT...THE SEVERE WEATHER THREAT DURING THIS
TIME WILL BE LOW ALTHOUGH THERE IS SOME POTENTIAL FOR HEAVY RAIN
AS STORMS MAY TRAIN ALONG THE FRONTAL ZONE.
FINALLY...THE SECOND AND STRONGER LOW PRESSURE SYSTEM DISCUSSED
EARLIER WILL MAKE FOR AN ACTIVE PERIOD WITH SEVERAL ROUNDS OF
THUNDERSTORMS BETWEEN SATURDAY NIGHT AND SUNDAY NIGHT. GIVEN THE
ENERGETIC NATURE OF THE SYSTEM THERE WILL AGAIN BE A POTENTIAL FOR
SEVERE WEATHER...HOWEVER AT THIS RANGE THE CRITICAL DETAILS OF
TRACK AND TIMING AND THUS THE REGION OF MAXIMUM SEVERE WEATHER
POTENTIAL REMAIN VERY UNCLEAR. IN ANY EVENT...IN WAKE OF THIS
WEEKEND SYSTEM IT APPEARS THAT A BRIEF RESPITE OF COOL AND QUIET
WEATHER MAY BE IN STORE FOR EARLY NEXT WEEK.
&&
.AVIATION...05/18Z
ISSUED AT 1238 PM CDT TUE MAY 5 2015
FRONTAL BOUNDARY IS DRAPED ACROSS THE THE STATE...LOCATED JUST
SOUTH OF FOD AND ALO SITES. WITH ALO AND FOD JUST NORTH OF THE
BOUNDARY...CIGS AND VSBY HAVE BEEN IN IFR AND MVFR MOST OF THE
DAY FROM. IMPROVEMENT AT THOSE SITES WILL BE SLOW AS CIGS
GRADUALLY MOVE TOWARDS VFR THIS EVENING AND OVERNIGHT AS THE FRONT
SLOWLY SHIFTS NORTH. DSM AND OTM SHOULD REMAIN VFR THROUGH MUCH OF
THE TAF PERIOD...WITH CHANCES OF FOG OVERNIGHT. THE NORTHERN SITES
MAY SEE PRECIPITATION THIS EVENING...INCLUDING OCCASIONAL
THUNDER...BUT NONE OF THE MODELS ARE IN GREAT AGREEMENT ON TIMING
AND INTENSITY...SO MENTIONED ONLY VCSH FOR NOW AT ALO AND MCW.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...CURTIS
LONG TERM...LEE
AVIATION...CURTIS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
228 AM MDT TUE MAY 5 2015
.UPDATE...
ISSUED AT 1023 PM MDT MON MAY 4 2015
UPDATED FORECAST TO REFLECT THE DIMINISHED CHANCES FOR RAINFALL
FOR THE WESTERN HALF OR SO OF THE AREA THROUGH THE REST OF THE
NIGHT. WAS VERY CONFIDENT EARLIER THAT THE LINE OF STORMS WOULD
MOVE ACROSS THE ENTIRE AREA...WITH SOME WEAKENING OVER THE EAST
PART OF THE AREA. HOWEVER OVER THE LAST HOUR OR SO THE LINE OF
STORMS HAS ALMOST COMPLETELY DISSIPATED.
LOOKING AT RUC THETA-E AT 850MB...THERE IS DRIER AIR OVER THE
WESTERN HALF OF THE AREA. AM THINKING THIS IS WHY THE STORMS DIED
OVER THE WEST INSTEAD OF THE EAST WHICH HAS HIGHER THETA-E AND
BETTER CAPE.
LOOKING SOUTHWARD NUMEROUS SHOWERS AND SOME T-STORMS CONTINUE
TO MOVE UP FROM THE SOUTH IN THE HIGHER THETA-E AIR. LIFT DOES
DECLINE OVER THE EAST OVERNIGHT SO HAVE RAINFALL CHANCES TRENDING
ACCORDINGLY. DOES LOOK LIKE THE EAST HALF WILL HAVE A MUCH BETTER
CHANCE FOR RAINFALL DUE TO THE HIGHER THETA-E AIR PRESENT.
MEANWHILE PATCHY FOG IS EXPECTED OVER THE NORTHERN HALF OR SO OF
THE AREA OVERNIGHT INTO TUESDAY MORNING. LOOKS LIKE THE FOG WILL
BE NORTH OF THE SLOWLY ADVANCING SURFACE BOUNDARY.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 220 PM MDT MON MAY 4 2015
EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW
DEEPENING TROUGH OVER SOUTHERN CALIFORNIA WITH SW FLOW FROM THE GULF
OF ALASKA AND ACROSS THE CENTRAL/HIGH PLAINS. MOIST PLUME EXTENDS
FROM THE GREAT BASIN ACROSS THE OHIO RIVER VALLEY WITH ADDITIONAL
MOISTURE FEEDING IN THE PLAINS FROM THE GULF OF MEXICO. AT THE
SURFACE A STATIONARY FRONT EXTENDS FROM NORTHEAST KANSAS TO
SOUTHEAST COLORADO AND LIES JUST SOUTHEAST OF OUR CWA...WITH
BAROCLINIC ZONE EXTENDING NORTH INTO THE SE PART OF OUR CWA.
THUNDERSTORMS ARE BEGINNING TO DEVELOP ALONG THIS FRONTAL ZONE
TOWARDS THE SOUTHEAST PART OF OUR CWA.
THIS AFTERNOON-EVENING...ALONG THIS FRONTAL ZONE ANALYSIS INDICATES
ML CAPE VALUES RANGING FROM 1500 J/KG IN THE WARM SECTOR TO 500
J/KG IN OUR SE CWA. BULK SHEER IS APPROXIMATELY 30-35KT...SO
DEPENDING ON POSITION OF FRONT (CURRENTLY ADVERTISED TO SLIDE NORTH
INTO OUR SOUTHEAST)...THERE IS THE POTENTIAL FOR A FEW STRONGER
THUNDERSTORMS...POSSIBLY SEVERE WITH LARGE HAIL/DAMAGING WINDS MAIN
THREAT. IF FRONT WERE TO LIFT NORTH AS WARM FRONT WE COULD SEE
BETTER SB/ML CAPE AND THE POSSIBILITY FOR A FEW MORE ORGANIZED CELLS
IN THE SOUTHEAST. ANALYSIS ALSO INDICATES PWAT VALUES ALREADY IN
EXCESS OF 1" OVER OUR EAST. STORM MOTIONS WILL BE ROUGHLY
TANGENTIAL/PARALLEL THIS AFTERNOON BECOMING PERPENDICULAR TO FRONTAL
ZONE THIS EVENING. AS THIS TRANSITION OCCURS THERE IS THE
FOR BACKBUILDING OR TRAINING AS VERY MOIST/UNSTABLE AIR IN THE WARM
SECTOR FEEDS NORTH. THERE COULD BE A THREAT FOR FLASH FLOODING IF
THIS SCENARIO PLAYS OUT. EITHER WAY WITH VERY MOIST AIR MASS AND
INCREASING ELEVATED INSTABILITY...THUNDERSTORMS COULD BE VERY
EFFICIENT RAINFALL PRODUCERS.
TONIGHT-TUESDAY...UPSTREAM AREAS OF MID LEVEL VORTICITY WILL ROTATE
INTO THE CWA WITH INCREASING LIFT LATE THIS EVENING INTO THE
OVERNIGHT. AS TROUGH CONTINUES TO DEEPEN OVER THE SW US AND MOVE
EAST WE WILL CONTINUE TO SEE VERY GOOD FORCING/MOISTURE ROTATES
THROUGH THE REGION. LARGE SCALE Q VECTOR FIELDS INDICATED FORCING
INCREASING THROUGH THE NIGHT AND OMEGA/MOISTURE
CONVERGENCE FIELDS SHOW SUPPORT FOR INCREASING COVERAGE/COMPLEX OF
SHOWERS THUNDERSTORMS. ELEVATED INSTABILITY TRANSITIONS NORTHWARD
AND WEAKENS...HOWEVER THERE IS ENOUGH TO KEEP THUNDER MENTION IN
PLACE THROUGH TUESDAY AFTERNOON. WHILE GUIDANCE IS IN AGREEMENT ON
GENERAL LARGE SCALE PATTERN THE MAIN DIFFERENCES ARE ON TIMING OF
POTENTIAL PERIODS OF HEAVIER PRECIP...WITH BEST PRECIP SIGNAL AND
MOISTURE PROFILES OVERLAPPING TUESDAY MORNING THROUGH TUESDAY
AFTERNOON ACROSS THE WESTERN 2/3 OF THE CWA (THOUGH ECMWF MIGHT BE A
LITTLE EAST). THERE WILL BE MODERATE/ELEVATED INSTABILITY IN PLACE
THROUGH THE DAY TUESDAY...SO STRONG TO SEVERE THUNDERSTORMS WILL
STILL BE POSSIBLE AGAIN...THOUGH SEVERE POTENTIAL MIGHT NOT BE AS
GOOD AS TODAY WITH WIDESPREAD SHOWERS AND STRATUS LIMITING SURFACE
BASED PARCELS AND ANY ACTIVITY LIKELY EMBEDDED WITH OTHER SHOWER
CLUSTERS.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 227 AM MDT TUE MAY 5 2015
A HIGH AMPLITUDE TROUGH WITH A CLOSED LOW WILL AFFECT THE TRI STATE
AREA TO START THE LONG TERM FORECAST PERIOD FRIDAY...WHICH WILL
BRING INCREASED CHANCES FOR SHOWERS AND THUNDERSTORMS ACROSS MUCH OF
THE FORECAST AREA FOR THE DURATION OF THE FORECAST PERIOD.
GFS/ECMWF/CANADIAN FORECASTS ALL INDICATE THE SLOW MOVING TROUGH
WILL AFFECT THE REGION FOR THE DURATION OF THE COMING WEEKEND. THE
TROUGH TAKES A NEGATIVE TILT SATURDAY IN THE GFS/ECMWF
FORECASTS...WHICH WILL STEEPEN LAPSE RATES ALOFT AND INCREASE CAPE
VALUES. A STRONGER JET MAY ALSO BE IN THE AREA TO HELP DESTABILIZE
THE ENVIRONMENT...BUT MODEL GUIDANCE DIFFERS AS TO THE ACTUAL
STRENGTH. GFS FORECAST HAS AN UPPER LEVEL JET APPROACHING 80KTS
OVER THE FORECAST AREA...WHICH IS PLENTY STRONG TO GIVE 0-6 KM BULK
SHEAR VALUES APPROACHING 50 KTS. LOWER LEVEL HODOGRAPHS ALSO HAVE
GOOD CURVATURE WITH 0-3 KM HELICITY APPROACHING CRITICAL VALUES FOR
TORNADOES. HOWEVER...ECMWF/CANADIAN MODELS ARE NOT AS ENTHUSIASTIC
AND HAVE BETTER JET LOCATED TO THE EAST OF OUR AREA.
THEREFORE...SEVERE THUNDERSTORM THREAT LOOKS TO BE POSSIBLE BUT NOT
DEFINITE AT THIS POINT.
HEAVY RAIN IS POSSIBLE SATURDAY NIGHT FOR MANY LOCATIONS DUE TO VERY
SATURATED MODEL SOUNDINGS AND CAPE IN THE PROFILE TO CONTINUE TO
DRIVE CONVECTION INTO THE EVENING. ALONG AN ADVANCING WARM
FRONT...AN MCS IS LIKELY TO DEVELOP AND BE PERSISTENT WITH THE
ENHANCEMENT OF THE LOWER NOCTURNAL JET. SHOWERS AND STORMS WILL
TAPER OFF TOWARDS SUNDAY MORNING. SCATTERED THUNDERSTORMS MAY
CONTINUE INTO THE AFTERNOON HOURS WITH THE UPPER LEVEL TROUGH
LINGERING IN THE AREA...BUT THE BASE OF THE TROUGH WILL PASS OVER
THE HIGH PLAINS MONDAY AND WILL EFFECTIVELY END THE HIGHER
PRECIPITATION THREAT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1142 PM MDT MON MAY 4 2015
MVFR TO IFR CONDITIONS FORECAST FOR THE 6Z TAFS. EXPECT CONDITIONS
AT KMCK TO REMAIN UNCHANGED UNTIL CLOSE TO MID MORNING. MEANWHILE
AT KGLD CEILINGS HAVE FLUCTUATED FROM IFR TO VFR OVER THE PAST
HOUR OR SO. EXPECT IFR CEILING IN THE NEXT HOUR. FOR BOTH SITES CEILINGS
SHOULD INCREASE TO MVFR DURING THE LATE MORNING...THEN FALL TO IFR
AGAIN IN THE EARLY EVENING.
THE SHOWERS SHOULD REMAIN SOUTH OF KMCK FOR THE REST OF THE NIGHT
AND THROUGH MOST OF THE DAY. DURING THE LATE AFTERNOON THERE MAY
BE A SHORT WINDOW FOR STORMS TO MOVE NEAR THE SITE...BUT WILL
WAIT FOR LATER TAFS TO ADDRESS THIS.
KGLD SHOULD REMAIN RAIN FREE TONIGHT. DURING THE LATE MORNING AND
THROUGH THE AFTERNOON RAIN CHANCES WILL INCREASE...WITH THE BEST
CHANCES DURING THE MID TO LATE AFTERNOON. BY EARLY EVENING THE
CHANCES FOR RAIN WILL BEGIN TO DECLINE.
EXPECT VISIBILITY REDUCTION FOR BOTH SITES DURING THE
OVERNIGHT HOURS. VISIBILITY SHOULD IMPROVE DURING THE MID TO LATE
MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...MK
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS WICHITA KS
313 AM CDT TUE MAY 5 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 307 AM CDT TUE MAY 5 2015
LINGERING SHOWERS AND THUNDERSTORMS CONTINUE ALONG A QUASI
STATIONARY BOUNDARY SITUATED JUST NORTH OF INTERSTATE 70 AT THIS
TIME. LATEST SHORT TERM HI-RES MODELS SUGGEST THIS BOUNDARY WILL
SLOWLY LIFT BACK TO THE NORTH THIS MORNING TOWARDS NEB...TAKING MOST
OF THE SHOWER ACTIVITY NORTH WITH IT. THIS WILL LEAD TO DRY
CONDITIONS FOR THE DAYTIME HOURS ACROSS THE FORECAST AREA...AS A
WARM ELEVATED MIXED LAYER CAPS OFF ANY PRECIP CHANCE WITH LESS
INSTABILITY THIS AFTERNOON.
THE MAIN DRYLINE AND CONVERGENCE FOR STORM CHANCES LOOKS TO SHIFT
INTO WESTERN KS FOR THIS AFTERNOON INTO THIS EVENING. THINK SHOWERS
AND THUNDERSTORMS WILL DEVELOP ALONG THIS DRYLINE AND MAKE SLOW
PROGRESS TO THE EAST...AS AN INITIAL SHORTWAVE ROTATES NORTH ACROSS
WESTERN KS LATE THIS AFTERNOON.
BUT EXPECT ANOTHER MORE POTENT SHORTWAVE TO ROTATE NORTH OUT OF SRN
NM DURING THE EVENING WITH THIS SHORTWAVE LIFTING NORTHEAST
ACROSS THE FORECAST AREA FOR THE LATE EVENING AND OVERNIGHT HOURS.
LIFT ASSOCIATED WITH THIS SHORTWAVE WILL LEAD TO SHOWERS INITIALLY
DEVELOPING IN OK...WITH THE STORMS MOVING NORTH INTO THE AREA
DURING THE LATE EVENING HOURS. AS THIS IMPULSE MOVES ACROSS THE
AREA...WIDESPREAD SHOWERS AND SOME EMBEDDED THUNDERSTORMS WILL
BLOSSOM ACROSS MOST OF THE FORECAST AREA FOR THE OVERNIGHT HOURS
AS THE UPPER LEVEL DIFFLUENCE INCREASES. PREVIOUS SHIFTS ADJUSTED
THE POP TIMING WITH CATEGORICAL POPS MAINLY AFTER 06Z...WITH
LIKELY POPS FOR THE EVENING HOURS. THIS LOOKS OKAY.
SOME UNCERTAINTY ON HOW EARLY WED WILL PLAY OUT...AS REMNANT SHOWERS
AND EMBEDDED THUNDER WILL STILL BE ACROSS CENTRAL KS FOR THE MORNING
HOURS. LOTS OF REMNANT CLOUD COVER WILL ALSO BE AROUND...AS
INSTABILITY INCREASES AND THE DRYLINE PUSHES EAST CLOSER TO THE
FORECAST AREA FOR WED AFTERNOON. IF AIRMASS CAN RECOVER...LATEST
NAM/WRF AND GFS SHOW A VERY UNSTABLE AIRMASS WILL BE IN PLACE ACROSS
SOUTH CENTRAL KS...WITH DEEP LAYER BULK SHEAR INCREASING TO AROUND
30-40 KTS. WEAKLY CAPPED ENVIRONMENT WILL BE IN PLACE..SO EXPECT
DISCRETE STORMS TO DEVELOP ALONG THIS DRYLINE FOR WED
AFTERNOON....WITH STORMS EXPECTED TO BECOME SUPERCELLS GIVEN THE
DIRECTIONAL SHEAR. THIS CERTAINLY LOOKS LIKE A SEVERE WEATHER THREAT
WITH LARGE HAIL AND DAMAGING WINDS THE MAIN CONCERN.
DRYLINE IS EXPECTED TO RETREAT BACK TO THE WEST DURING THE NIGHTTIME
HOURS ON WED...SO NOT ENTIRELY SURE HOW LONG THE CONVECTION WILL
CONTINUE INTO WED NIGHT...AS SOME WARMER AIR ALOFT WILL EFFECTIVELY
SHUT DOWN THE CONVECTION.
THE DRYLINE WILL AGAIN COME INTO PLAY ON THU...AS THE BOUNDARY
BECOMES MORE OF A COLD FRONT AND AGAIN PUSHES INTO PORTIONS OF
CENTRAL KS FOR THU AFTERNOON AS A NORTHERN STREAM SYSTEM HELPS PUSH
IT FURTHER EAST.
INSTABILITY AND SHEAR SUGGESTS ANOTHER ROUND OF SEVERE WEATHER MAY
OCCUR ALONG THIS BOUNDARY FOR PORTIONS OF THE FORECAST AREA FOR THU
AFTERNOON/EVENING...AS SUPERCELLS WILL AGAIN BE POSSIBLE. WILL HAVE
TO KEEP AN EYE ON THIS SEVERE WEATHER THREAT...AS AN AREA OF LOW
PRESSURE IN THE OK PANHANDLE MAY SETUP A TRIPLE POINT ACROSS SOUTH
CENTRAL KS...WITH SURFACE WINDS BACKING ACROSS SRN KS AND BETTER LOW
LEVEL TURNING FOR A POSSIBLE INCREASED TORNADO THREAT. STAY TUNED.
KETCHAM
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 307 AM CDT TUE MAY 5 2015
THE ACTIVE PATTERN LOOKS TO CONTINUE FOR FRI AND SAT...AS THE MAIN
SURFACE BOUNDARY BECOMES STATIONARY ACROSS SOUTHERN KS ON FRI
AFTERNOON. THE MID LEVEL BAROCLINIC ZONE WILL ALSO REMAIN CO-
LOCATED WITH THE SURFACE BOUNDARY AS WELL....WITH SHOWER AND
THUNDERSTORMS EXPECTED TO REDEVELOP ACROSS SOUTHERN KS AS THE LOW
LEVEL JET INCREASES OVER THE TOP OF THE BOUNDARY. THIS HAS ALL THE
SIGNS OF A SEVERE WEATHER PRODUCING COMPLEX OF STORMS (MCS)
DEVELOPING LATE FRI NIGHT ACROSS SRN KS...CONSIDERING THE AMOUNT OF
INSTABILITY THAT WILL BE AROUND AND BULK SHEAR OF 40 KTS.
HOW SAT WILL PLAY OUT WILL DEPEND ON WHERE THE MCS LATE FRI NIGHT
GOES AND ANY OUTFLOW BOUNDARY IT PUSHES OUT. MEDIUM RANGE MODELS
SUGGEST THAT A VIGOROUS SHORTWAVE IS EXPECTED TO LIFT NORTHEAST OUT
OF THE SOUTHERN PLAINS ON SAT EVENING AND WILL PUSH ANY KIND OF
BOUNDARY/WARM FRONT BACK NORTH ACROSS THE AREA FOR SAT NIGHT...WHICH
WILL LEAD TO ANOTHER CHANCE OF SEVERE STORMS FOR SAT NIGHT AS WELL.
WILL CERTAINLY HAVE TO KEEP AN EYE ON WATER ISSUES GOING INTO THE
WEEKEND...AS MOST OF THE CONVECTION WILL BE VERY EFFECTIVE RAINFALL
PRODUCERS FOR HEAVY RAINFALL AND POSSIBLE FLOODING CONCERNS.
KETCHAM
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1150 PM CDT MON MAY 4 2015
STORMS HAVE BEEN A BIT SLOWER TO EXIT CENTRAL KS THAN ANTICIPATED...
BUT SHORT TERM MODELS ARE STILL ADAMANT THAT PRECIPITATION WILL
PUSH NORTH EARLY IN THE FORECAST. LATEST RAP IS A BIT DIFFERENT
KEEPING OUTFLOW/SURFACE BOUNDARY QUASISTATIONARY BUT STILL MOVING
PRECIPITATION TO THE NORTH. THIS SEEMS PLAUSIBLE BASED ON RADAR
TRENDS. FOCUS THEN TURNS TO TIMING OF CONVECTION TOMORROW.
OUTFLOW BOUNDARY MIGHT FOCUS INITIAL UPDRAFTS...BUT INABILITY TO
ACCURATELY FORECAST ITS LOCATION PRECLUDES AN EARLY MENTION IN
TAFS. WILL STICK WITH HIGHER PROBABILITY OF JUST PRIOR TO 0000
UTC AT KRSL/KHUT AND AFTER 0000 UTC AT KSLN/KHUT. HAVE KEPT KCNU
DRY FOR NOW...BUT ROGUE CELL COULD AFFECT KCNU DURING PK HEATING.
-HOWERTON
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 77 62 77 65 / 10 90 60 40
HUTCHINSON 76 61 76 63 / 10 90 50 50
NEWTON 74 60 75 62 / 10 90 60 40
ELDORADO 79 62 75 64 / 10 90 70 40
WINFIELD-KWLD 77 63 76 65 / 10 90 60 40
RUSSELL 75 59 78 60 / 40 80 50 50
GREAT BEND 73 59 78 62 / 50 80 40 40
SALINA 78 61 76 65 / 10 90 50 50
MCPHERSON 75 61 75 63 / 10 90 50 50
COFFEYVILLE 78 63 75 65 / 10 80 80 40
CHANUTE 79 62 75 64 / 10 70 80 30
IOLA 78 62 75 64 / 10 70 80 30
PARSONS-KPPF 79 63 75 65 / 10 70 80 30
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1149 PM MDT MON MAY 4 2015
.UPDATE...
ISSUED AT 1023 PM MDT MON MAY 4 2015
UPDATED FORECAST TO REFLECT THE DIMINISHED CHANCES FOR RAINFALL
FOR THE WESTERN HALF OR SO OF THE AREA THROUGH THE REST OF THE
NIGHT. WAS VERY CONFIDENT EARLIER THAT THE LINE OF STORMS WOULD
MOVE ACROSS THE ENTIRE AREA...WITH SOME WEAKENING OVER THE EAST
PART OF THE AREA. HOWEVER OVER THE LAST HOUR OR SO THE LINE OF
STORMS HAS ALMOST COMPLETELY DISSIPATED.
LOOKING AT RUC THETA-E AT 850MB...THERE IS DRIER AIR OVER THE
WESTERN HALF OF THE AREA. AM THINKING THIS IS WHY THE STORMS DIED
OVER THE WEST INSTEAD OF THE EAST WHICH HAS HIGHER THETA-E AND
BETTER CAPE.
LOOKING SOUTHWARD NUMEROUS SHOWERS AND SOME T-STORMS CONTINUE
TO MOVE UP FROM THE SOUTH IN THE HIGHER THETA-E AIR. LIFT DOES
DECLINE OVER THE EAST OVERNIGHT SO HAVE RAINFALL CHANCES TRENDING
ACCORDINGLY. DOES LOOK LIKE THE EAST HALF WILL HAVE A MUCH BETTER
CHANCE FOR RAINFALL DUE TO THE HIGHER THETA-E AIR PRESENT.
MEANWHILE PATCHY FOG IS EXPECTED OVER THE NORTHERN HALF OR SO OF
THE AREA OVERNIGHT INTO TUESDAY MORNING. LOOKS LIKE THE FOG WILL
BE NORTH OF THE SLOWLY ADVANCING SURFACE BOUNDARY.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 220 PM MDT MON MAY 4 2015
EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW
DEEPENING TROUGH OVER SOUTHERN CALIFORNIA WITH SW FLOW FROM THE GULF
OF ALASKA AND ACROSS THE CENTRAL/HIGH PLAINS. MOIST PLUME EXTENDS
FROM THE GREAT BASIN ACROSS THE OHIO RIVER VALLEY WITH ADDITIONAL
MOISTURE FEEDING IN THE PLAINS FROM THE GULF OF MEXICO. AT THE
SURFACE A STATIONARY FRONT EXTENDS FROM NORTHEAST KANSAS TO
SOUTHEAST COLORADO AND LIES JUST SOUTHEAST OF OUR CWA...WITH
BAROCLINIC ZONE EXTENDING NORTH INTO THE SE PART OF OUR CWA.
THUNDERSTORMS ARE BEGINNING TO DEVELOP ALONG THIS FRONTAL ZONE
TOWARDS THE SOUTHEAST PART OF OUR CWA.
THIS AFTERNOON-EVENING...ALONG THIS FRONTAL ZONE ANALYSIS INDICATES
ML CAPE VALUES RANGING FROM 1500 J/KG IN THE WARM SECTOR TO 500
J/KG IN OUR SE CWA. BULK SHEER IS APPROXIMATELY 30-35KT...SO
DEPENDING ON POSITION OF FRONT (CURRENTLY ADVERTISED TO SLIDE NORTH
INTO OUR SOUTHEAST)...THERE IS THE POTENTIAL FOR A FEW STRONGER
THUNDERSTORMS...POSSIBLY SEVERE WITH LARGE HAIL/DAMAGING WINDS MAIN
THREAT. IF FRONT WERE TO LIFT NORTH AS WARM FRONT WE COULD SEE
BETTER SB/ML CAPE AND THE POSSIBILITY FOR A FEW MORE ORGANIZED CELLS
IN THE SOUTHEAST. ANALYSIS ALSO INDICATES PWAT VALUES ALREADY IN
EXCESS OF 1" OVER OUR EAST. STORM MOTIONS WILL BE ROUGHLY
TANGENTIAL/PARALLEL THIS AFTERNOON BECOMING PERPENDICULAR TO FRONTAL
ZONE THIS EVENING. AS THIS TRANSITION OCCURS THERE IS THE
FOR BACKBUILDING OR TRAINING AS VERY MOIST/UNSTABLE AIR IN THE WARM
SECTOR FEEDS NORTH. THERE COULD BE A THREAT FOR FLASH FLOODING IF
THIS SCENARIO PLAYS OUT. EITHER WAY WITH VERY MOIST AIR MASS AND
INCREASING ELEVATED INSTABILITY...THUNDERSTORMS COULD BE VERY
EFFICIENT RAINFALL PRODUCERS.
TONIGHT-TUESDAY...UPSTREAM AREAS OF MID LEVEL VORTICITY WILL ROTATE
INTO THE CWA WITH INCREASING LIFT LATE THIS EVENING INTO THE
OVERNIGHT. AS TROUGH CONTINUES TO DEEPEN OVER THE SW US AND MOVE
EAST WE WILL CONTINUE TO SEE VERY GOOD FORCING/MOISTURE ROTATES
THROUGH THE REGION. LARGE SCALE Q VECTOR FIELDS INDICATED FORCING
INCREASING THROUGH THE NIGHT AND OMEGA/MOISTURE
CONVERGENCE FIELDS SHOW SUPPORT FOR INCREASING COVERAGE/COMPLEX OF
SHOWERS THUNDERSTORMS. ELEVATED INSTABILITY TRANSITIONS NORTHWARD
AND WEAKENS...HOWEVER THERE IS ENOUGH TO KEEP THUNDER MENTION IN
PLACE THROUGH TUESDAY AFTERNOON. WHILE GUIDANCE IS IN AGREEMENT ON
GENERAL LARGE SCALE PATTERN THE MAIN DIFFERENCES ARE ON TIMING OF
POTENTIAL PERIODS OF HEAVIER PRECIP...WITH BEST PRECIP SIGNAL AND
MOISTURE PROFILES OVERLAPPING TUESDAY MORNING THROUGH TUESDAY
AFTERNOON ACROSS THE WESTERN 2/3 OF THE CWA (THOUGH ECMWF MIGHT BE A
LITTLE EAST). THERE WILL BE MODERATE/ELEVATED INSTABILITY IN PLACE
THROUGH THE DAY TUESDAY...SO STRONG TO SEVERE THUNDERSTORMS WILL
STILL BE POSSIBLE AGAIN...THOUGH SEVERE POTENTIAL MIGHT NOT BE AS
GOOD AS TODAY WITH WIDESPREAD SHOWERS AND STRATUS LIMITING SURFACE
BASED PARCELS AND ANY ACTIVITY LIKELY EMBEDDED WITH OTHER SHOWER
CLUSTERS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 124 PM MDT MON MAY 4 2015
MAIN TROUGH AXIS WILL LIFT NORTHEAST ACROSS THE AREA TUESDAY NIGHT
WITH GOOD CHANCES FOR SHOWERS AND THUNDERSTORMS CONTINUING. AFTER
MIDNIGHT...GENERAL TREND WILL BE FOR A WEST TO EAST END OF THE
PRECIPITATION AS DRY SLOT WORKS IN BEHIND THE TROUGH. AFTER A LULL
WEDNESDAY MORNING...WRAPAROUND PRECIPITATION WILL MOVE IN FROM
COLORADO WEDNESDAY AFTERNOON AND BECOME WIDESPREAD WEDNESDAY
NIGHT. A COLD FRONT WILL ALSO MOVE THROUGH WEDNESDAY NIGHT WHICH
WILL PROVIDE A FOCUS FOR THUNDERSTORMS IN THE EVENING...BUT THE
POST FRONTAL ENVIRONMENT HAS ONLY LIMITED ELEVATED INSTABILITY AND
EXPECT ONLY ISOLATED THUNDERSTORMS THROUGH THURSDAY MORNING.
HOWEVER BY THURSDAY AFTERNOON SBCAPE INCREASES ONCE AGAIN AND A
COMBINATION OF MOIST LOW LEVEL UPSLOPE AND ANOTHER SHORTWAVE
TROUGH IN THE SOUTHWESTERLY FLOW ALOFT WILL RESULT IN THUNDERSTORM
DEVELOPMENT IN EASTERN COLORADO WHICH WILL MOVE INTO NORTHWEST
KANSAS AND SOUTHWEST NEBRASKA THURSDAY EVENING. SEVERE THREAT WILL
DEPEND ON HOW MUCH INSTABILITY CAN DEVELOP AFTER A CLOUDY
MORNING...BUT DEEP LAYER SHEAR WOULD BE SUPPORTIVE OF ORGANIZED
UPDRAFTS THROUGH EARLY EVENING BEFORE BOUNDARY LAYER DECOUPLES
WITH NOCTURNAL COOLING.
OVERALL PATTERN CHANGES LITTLE ON FRIDAY ALTHOUGH MODELS SHOWING
ONLY MINIMAL SBCAPE AVAILABLE SO SEVERE THREAT MAY NOT BE AS
GREAT. ANOTHER STRONG UPPER LOW WILL KICK OUT OF THE DESERT
SOUTHWEST ON SATURDAY WITH A NEGATIVE TILT AND PROVIDE THE
SYNOPTIC SCALE FORCING FOR THUNDERSTORMS. THE PATTERN SUGGESTS A
SEVERE THREAT WITH MODELS SHOWING DEEP LAYER SHEAR OF OVER 50KTS
AND SUFFICIENT INSTABILITY FOR SUPERCELLS. IF CURRENT TIMING
TRENDS CONTINUE WOULD EXPECT TO SEE A DRY SLOT SATURDAY NIGHT
FOLLOWED BY WRAPAROUND PRECIPITATION CHANCES ON SUNDAY.
THE PATTERN FINALLY CHANGES BY EARLY NEXT WEEK WITH SUBTLE
SHORTWAVE RIDGING IN A ZONAL FLOW WHICH WOULD TRANSLATE TO DRY
CONDITIONS AND SEASONABLE TEMPERATURES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1142 PM MDT MON MAY 4 2015
MVFR TO IFR CONDITIONS FORECAST FOR THE 6Z TAFS. EXPECT CONDITIONS
AT KMCK TO REMAIN UNCHANGED UNTIL CLOSE TO MID MORNING. MEANWHILE
AT KGLD CEILINGS HAVE FLUCTUATED FROM IFR TO VFR OVER THE PAST
HOUR OR SO. EXPECT IFR CEILING IN THE NEXT HOUR. FOR BOTH SITES CEILINGS
SHOULD INCREASE TO MVFR DURING THE LATE MORNING...THEN FALL TO IFR
AGAIN IN THE EARLY EVENING.
THE SHOWERS SHOULD REMAIN SOUTH OF KMCK FOR THE REST OF THE NIGHT
AND THROUGH MOST OF THE DAY. DURING THE LATE AFTERNOON THERE MAY
BE A SHORT WINDOW FOR STORMS TO MOVE NEAR THE SITE...BUT WILL
WAIT FOR LATER TAFS TO ADDRESS THIS.
KGLD SHOULD REMAIN RAIN FREE TONIGHT. DURING THE LATE MORNING AND
THROUGH THE AFTERNOON RAIN CHANCES WILL INCREASE...WITH THE BEST
CHANCES DURING THE MID TO LATE AFTERNOON. BY EARLY EVENING THE
CHANCES FOR RAIN WILL BEGIN TO DECLINE.
EXPECT VISIBILITY REDUCTION FOR BOTH SITES DURING THE
OVERNIGHT HOURS. VISIBILITY SHOULD IMPROVE DURING THE MID TO LATE
MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...024
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS WICHITA KS
1153 PM CDT MON MAY 4 2015
...UPDATED FOR 06Z AVIATION DISCUSSION...
.UPDATE...
ISSUED AT 839 PM CDT MON MAY 4 2015
CURRENT THINKING BASED ON QUICK LOOK AT 00Z DATA AND RECENT HI RES
MODELS SUG STORMS MAY HANG ON A BIT LONGER...BUT SHOULD DIMINISH
SHORTLY AFTER MIDNIGHT. APPEARS THAT 30-35KT 850MB JET IS
IMPINGING ON THE 850MB BOUNDARY THAT EXTENDS FROM NORTHEAST TO
SOUTHWEST ACROSS THE STATE. SEVERE THUNDERSTORM WATCH WILL EXPIRE
ON SCHEDULE AS STORMS HAVE CONTINUED TO SHOW A SLOW WEAKENING
TREND.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 312 PM CDT MON MAY 4 2015
DEEP MOIST CONVECTION IS EXPECTED TO DEVELOP THIS AFTERNOON AND
EVENING ALONG A STALLED FRONTAL BOUNDARY ACROSS CENTRAL KS WHERE THE
HIGHEST POPS WILL BE MAINTAINED. OTHER MORE ISOLATED DIURNALLY
DRIVEN ACTIVITY WILL BE POSSIBLE THROUGH EARLY EVENING ACROSS
SOUTHERN KANSAS. SOME OF THE HIGHER RESOLUTION MODEL GUIDANCE IS
SUGGESTING THAT OUTFLOW WILL FORCE THE BOUNDARY FURTHER SOUTH AND
TRENDED POPS UP SLIGHTLY ACROSS PORTIONS OF SOUTH CENTRAL AND
SOUTHEAST KS TO ACCOUNT FOR THIS SCENARIO. BY 07-09Z THE WARM
FRONT IS EXPECTED TO LIFT NORTH BRINGING AN END TO ANY LINGERING
PRECIPITATION.
MUCH OF TUESDAY MAY BE DRY BUT MAINTAINED MID POPS ACROSS PORTIONS
OF CENTRAL AND SOUTH CENTRAL KANSAS AS ANY ACTIVITY DEVELOPING
ACROSS SW KS MAY DRIFT NORTHEAST ACROSS THE AREA LATER IN THE DAY
AND THE AIRMASS IS PROGGED TO REMAIN WEAKLY CAPPED. BETTER CHANCES
FOR MORE WIDESPREAD PRECIPITATION WILL ARRIVE LATE TUE NIGHT INTO
EARLY WED AS A VIGOROUS SHORTWAVE TROUGH EMERGES OVER THE CENTRAL
HIGH PLAINS. THIS WAS HANDLED WELL IN THE PREVIOUS FORECAST AND
THE PRIMARY CHANGE WAS TO SLOW POPS WITH THE HIGHEST PROBABILITIES
ARRIVING AFTER 06Z ACROSS THE FORECAST AREA.
WED-THU...THE DEEP LAYER SHEAR IS PROGGED TO INCREASE ON WED AS THE
FOCUS FOR DEEP MOIST CONVECTION IS EXPECTED TO DEVELOP ALONG HWY 281
ALONG A DRYLINE. MAINTAINED MID POPS WED NIGHT INTO THU AS THE
AIRMASS IS PROGGED TO REMAIN UNSTABLE WITH A CONTINUATION OF
SOUTHWEST MID/UPPER FLOW. TIMING ANY SHORTWAVE TROUGHS LIFTING OUT
OF THE SOUTHWEST BECOMES CHALLENGING AT THIS POINT.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 312 PM CDT MON MAY 4 2015
A MID/UPPER TROUGH OVER THE SOUTHWEST AT THE BEGINNING OF
THE PERIOD IS PROGGED TO MOVE EAST/NORTHEAST INTO THE SOUTHERN
AND CENTRAL ROCKIES OVER THE WEEKEND. RICH MOISTURE IS PROGGED TO
REMAIN ENTRENCHED ACROSS THE SOUTHERN AND CENTRAL PLAINS STATES
WHERE MULTIPLE ROUNDS OF DEEP MOIST CONVECTION ARE EXPECTED LATE
IN THE WEEK AND INTO THE WEEKEND. MAINTAINED MID POPS THROUGH MUCH
OF THE PERIOD WITH SEASONABLY MILD TEMPERATURES ANTICIPATED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1150 PM CDT MON MAY 4 2015
STORMS HAVE BEEN A BIT SLOWER TO EXIT CENTRAL KS THAN ANTICIPATED...
BUT SHORT TERM MODELS ARE STILL ADAMANT THAT PRECIPITATION WILL
PUSH NORTH EARLY IN THE FORECAST. LATEST RAP IS A BIT DIFFERENT
KEEPING OUTFLOW/SURFACE BOUNDARY QUASISTATIONARY BUT STILL MOVING
PRECIPITATION TO THE NORTH. THIS SEEMS PLAUSIBLE BASED ON RADAR
TRENDS. FOCUS THEN TURNS TO TIMING OF CONVECTION TOMORROW.
OUTFLOW BOUNDARY MIGHT FOCUS INITIAL UPDRAFTS...BUT INABILITY TO
ACCURATELY FORECAST ITS LOCATION PRECLUDES AN EARLY MENTION IN
TAFS. WILL STICK WITH HIGHER PROBABILITY OF JUST PRIOR TO 0000
UTC AT KRSL/KHUT AND AFTER 0000 UTC AT KSLN/KHUT. HAVE KEPT KCNU
DRY FOR NOW...BUT ROGUE CELL COULD AFFECT KCNU DURING PK HEATING.
-HOWERTON
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 62 77 63 77 / 20 20 90 60
HUTCHINSON 62 76 61 77 / 40 20 90 50
NEWTON 61 74 59 73 / 20 10 90 60
ELDORADO 61 79 63 76 / 10 10 90 70
WINFIELD-KWLD 61 77 62 76 / 10 20 90 60
RUSSELL 59 75 59 78 / 70 50 80 50
GREAT BEND 59 73 59 78 / 90 60 80 40
SALINA 61 78 61 77 / 90 20 90 50
MCPHERSON 61 75 60 74 / 50 20 90 50
COFFEYVILLE 59 78 63 74 / 10 20 80 80
CHANUTE 60 79 63 75 / 10 10 70 80
IOLA 60 78 63 73 / 10 10 70 80
PARSONS-KPPF 59 79 63 75 / 10 20 70 80
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1030 PM MDT MON MAY 4 2015
.UPDATE...
ISSUED AT 1023 PM MDT MON MAY 4 2015
UPDATED FORECAST TO REFLECT THE DIMINISHED CHANCES FOR RAINFALL
FOR THE WESTERN HALF OR SO OF THE AREA THROUGH THE REST OF THE
NIGHT. WAS VERY CONFIDENT EARLIER THAT THE LINE OF STORMS WOULD
MOVE ACROSS THE ENTIRE AREA...WITH SOME WEAKENING OVER THE EAST
PART OF THE AREA. HOWEVER OVER THE LAST HOUR OR SO THE LINE OF
STORMS HAS ALMOST COMPLETELY DISSIPATED.
LOOKING AT RUC THETA-E AT 850MB...THERE IS DRIER AIR OVER THE
WESTERN HALF OF THE AREA. AM THINKING THIS IS WHY THE STORMS DIED
OVER THE WEST INSTEAD OF THE EAST WHICH HAS HIGHER THETA-E AND
BETTER CAPE.
LOOKING SOUTHWARD NUMEROUS SHOWERS AND SOME T-STORMS CONTINUE
TO MOVE UP FROM THE SOUTH IN THE HIGHER THETA-E AIR. LIFT DOES
DECLINE OVER THE EAST OVERNIGHT SO HAVE RAINFALL CHANCES TRENDING
ACCORDINGLY. DOES LOOK LIKE THE EAST HALF WILL HAVE A MUCH BETTER
CHANCE FOR RAINFALL DUE TO THE HIGHER THETA-E AIR PRESENT.
MEANWHILE PATCHY FOG IS EXPECTED OVER THE NORTHERN HALF OR SO OF
THE AREA OVERNIGHT INTO TUESDAY MORNING. LOOKS LIKE THE FOG WILL
BE NORTH OF THE SLOWLY ADVANCING SURFACE BOUNDARY.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 220 PM MDT MON MAY 4 2015
EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW
DEEPENING TROUGH OVER SOUTHERN CALIFORNIA WITH SW FLOW FROM THE GULF
OF ALASKA AND ACROSS THE CENTRAL/HIGH PLAINS. MOIST PLUME EXTENDS
FROM THE GREAT BASIN ACROSS THE OHIO RIVER VALLEY WITH ADDITIONAL
MOISTURE FEEDING IN THE PLAINS FROM THE GULF OF MEXICO. AT THE
SURFACE A STATIONARY FRONT EXTENDS FROM NORTHEAST KANSAS TO
SOUTHEAST COLORADO AND LIES JUST SOUTHEAST OF OUR CWA...WITH
BAROCLINIC ZONE EXTENDING NORTH INTO THE SE PART OF OUR CWA.
THUNDERSTORMS ARE BEGINNING TO DEVELOP ALONG THIS FRONTAL ZONE
TOWARDS THE SOUTHEAST PART OF OUR CWA.
THIS AFTERNOON-EVENING...ALONG THIS FRONTAL ZONE ANALYSIS INDICATES
ML CAPE VALUES RANGING FROM 1500 J/KG IN THE WARM SECTOR TO 500
J/KG IN OUR SE CWA. BULK SHEER IS APPROXIMATELY 30-35KT...SO
DEPENDING ON POSITION OF FRONT (CURRENTLY ADVERTISED TO SLIDE NORTH
INTO OUR SOUTHEAST)...THERE IS THE POTENTIAL FOR A FEW STRONGER
THUNDERSTORMS...POSSIBLY SEVERE WITH LARGE HAIL/DAMAGING WINDS MAIN
THREAT. IF FRONT WERE TO LIFT NORTH AS WARM FRONT WE COULD SEE
BETTER SB/ML CAPE AND THE POSSIBILITY FOR A FEW MORE ORGANIZED CELLS
IN THE SOUTHEAST. ANALYSIS ALSO INDICATES PWAT VALUES ALREADY IN
EXCESS OF 1" OVER OUR EAST. STORM MOTIONS WILL BE ROUGHLY
TANGENTIAL/PARALLEL THIS AFTERNOON BECOMING PERPENDICULAR TO FRONTAL
ZONE THIS EVENING. AS THIS TRANSITION OCCURS THERE IS THE
FOR BACKBUILDING OR TRAINING AS VERY MOIST/UNSTABLE AIR IN THE WARM
SECTOR FEEDS NORTH. THERE COULD BE A THREAT FOR FLASH FLOODING IF
THIS SCENARIO PLAYS OUT. EITHER WAY WITH VERY MOIST AIR MASS AND
INCREASING ELEVATED INSTABILITY...THUNDERSTORMS COULD BE VERY
EFFICIENT RAINFALL PRODUCERS.
TONIGHT-TUESDAY...UPSTREAM AREAS OF MID LEVEL VORTICITY WILL ROTATE
INTO THE CWA WITH INCREASING LIFT LATE THIS EVENING INTO THE
OVERNIGHT. AS TROUGH CONTINUES TO DEEPEN OVER THE SW US AND MOVE
EAST WE WILL CONTINUE TO SEE VERY GOOD FORCING/MOISTURE ROTATES
THROUGH THE REGION. LARGE SCALE Q VECTOR FIELDS INDICATED FORCING
INCREASING THROUGH THE NIGHT AND OMEGA/MOISTURE
CONVERGENCE FIELDS SHOW SUPPORT FOR INCREASING COVERAGE/COMPLEX OF
SHOWERS THUNDERSTORMS. ELEVATED INSTABILITY TRANSITIONS NORTHWARD
AND WEAKENS...HOWEVER THERE IS ENOUGH TO KEEP THUNDER MENTION IN
PLACE THROUGH TUESDAY AFTERNOON. WHILE GUIDANCE IS IN AGREEMENT ON
GENERAL LARGE SCALE PATTERN THE MAIN DIFFERENCES ARE ON TIMING OF
POTENTIAL PERIODS OF HEAVIER PRECIP...WITH BEST PRECIP SIGNAL AND
MOISTURE PROFILES OVERLAPPING TUESDAY MORNING THROUGH TUESDAY
AFTERNOON ACROSS THE WESTERN 2/3 OF THE CWA (THOUGH ECMWF MIGHT BE A
LITTLE EAST). THERE WILL BE MODERATE/ELEVATED INSTABILITY IN PLACE
THROUGH THE DAY TUESDAY...SO STRONG TO SEVERE THUNDERSTORMS WILL
STILL BE POSSIBLE AGAIN...THOUGH SEVERE POTENTIAL MIGHT NOT BE AS
GOOD AS TODAY WITH WIDESPREAD SHOWERS AND STRATUS LIMITING SURFACE
BASED PARCELS AND ANY ACTIVITY LIKELY EMBEDDED WITH OTHER SHOWER
CLUSTERS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 124 PM MDT MON MAY 4 2015
MAIN TROUGH AXIS WILL LIFT NORTHEAST ACROSS THE AREA TUESDAY NIGHT
WITH GOOD CHANCES FOR SHOWERS AND THUNDERSTORMS CONTINUING. AFTER
MIDNIGHT...GENERAL TREND WILL BE FOR A WEST TO EAST END OF THE
PRECIPITATION AS DRY SLOT WORKS IN BEHIND THE TROUGH. AFTER A LULL
WEDNESDAY MORNING...WRAPAROUND PRECIPITATION WILL MOVE IN FROM
COLORADO WEDNESDAY AFTERNOON AND BECOME WIDESPREAD WEDNESDAY
NIGHT. A COLD FRONT WILL ALSO MOVE THROUGH WEDNESDAY NIGHT WHICH
WILL PROVIDE A FOCUS FOR THUNDERSTORMS IN THE EVENING...BUT THE
POST FRONTAL ENVIRONMENT HAS ONLY LIMITED ELEVATED INSTABILITY AND
EXPECT ONLY ISOLATED THUNDERSTORMS THROUGH THURSDAY MORNING.
HOWEVER BY THURSDAY AFTERNOON SBCAPE INCREASES ONCE AGAIN AND A
COMBINATION OF MOIST LOW LEVEL UPSLOPE AND ANOTHER SHORTWAVE
TROUGH IN THE SOUTHWESTERLY FLOW ALOFT WILL RESULT IN THUNDERSTORM
DEVELOPMENT IN EASTERN COLORADO WHICH WILL MOVE INTO NORTHWEST
KANSAS AND SOUTHWEST NEBRASKA THURSDAY EVENING. SEVERE THREAT WILL
DEPEND ON HOW MUCH INSTABILITY CAN DEVELOP AFTER A CLOUDY
MORNING...BUT DEEP LAYER SHEAR WOULD BE SUPPORTIVE OF ORGANIZED
UPDRAFTS THROUGH EARLY EVENING BEFORE BOUNDARY LAYER DECOUPLES
WITH NOCTURNAL COOLING.
OVERALL PATTERN CHANGES LITTLE ON FRIDAY ALTHOUGH MODELS SHOWING
ONLY MINIMAL SBCAPE AVAILABLE SO SEVERE THREAT MAY NOT BE AS
GREAT. ANOTHER STRONG UPPER LOW WILL KICK OUT OF THE DESERT
SOUTHWEST ON SATURDAY WITH A NEGATIVE TILT AND PROVIDE THE
SYNOPTIC SCALE FORCING FOR THUNDERSTORMS. THE PATTERN SUGGESTS A
SEVERE THREAT WITH MODELS SHOWING DEEP LAYER SHEAR OF OVER 50KTS
AND SUFFICIENT INSTABILITY FOR SUPERCELLS. IF CURRENT TIMING
TRENDS CONTINUE WOULD EXPECT TO SEE A DRY SLOT SATURDAY NIGHT
FOLLOWED BY WRAPAROUND PRECIPITATION CHANCES ON SUNDAY.
THE PATTERN FINALLY CHANGES BY EARLY NEXT WEEK WITH SUBTLE
SHORTWAVE RIDGING IN A ZONAL FLOW WHICH WOULD TRANSLATE TO DRY
CONDITIONS AND SEASONABLE TEMPERATURES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 555 PM MDT MON MAY 4 2015
VFR TO LIFR CONDITIONS FOR THE TAFS. CHALLENGING SET OF TAFS DUE
TO TIMING OF THE DIFFERENT WAVES OF RAINFALL...THE CEILING
HEIGHTS AND VISIBILITY. IN GENERAL LOOKS LIKE KGLD WILL HAVE A
BETTER CHANCE FOR RECEIVING RAINFALL THAN KMCK...ESPECIALLY
PROLONGED RAINFALL. BASED TIMING OF THE STORMS FOR BOTH SITES BY
TRACKING THE SPEED OF THE CURRENT STORMS. IF STORM MOVEMENT
CHANGES THAT WILL AFFECT THE TIMING IN THE TAFS. BASED ON
OBSERVATIONS AND MODEL SOUNDINGS...LOOKS LIKE THE SECOND WAVE OF
STORMS WILL CAUSE CEILINGS TO FALL. OVERNIGHT VISIBILITIES WILL
DECLINE SOME BUT THEN IMPROVE BY MID MORNING. HAVE VC FOR KMCK DUE
TO UNCERTAINTY THERE WILL STILL BE RAINFALL AT THE SITE DURING THE
MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...024
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1149 PM CDT MON MAY 4 2015
.AVIATION...A FEW SHOWERS WILL AFFECT KLCH AND KBPT THROUGH THE
NEXT FEW HOURS AND THESE SHOWERS MAY LINGER THROUGH THE NIGHT. A
FEW TSRA MAY BE IN VICINITY OF THESE TERMINAL TOMORROW, HOWEVER
COVERAGE WILL DECREASE AS SUNSET APPROACHES. WITH ANY SHOWER MVFR
CEILINGS AND VIS MAY OCCUR. LIGHT SE WINDS WILL PREVAIL TONIGHT
WITH WINDS BECOMING GUSTY BY MID MORNING TUE.
&&
.PREV DISCUSSION... /ISSUED 1036 PM CDT MON MAY 4 2015/
UPDATE...
WEAK INVERTED TROF/ELY WAVE CONTINUES ITS TREK WEST...CURRENTLY
LOCATED ROUGHLY SOUTH OF THE CAMERON/VERMILION PARISH LINE. LATEST
KLCH RADAR SHOWS ISLTD SHOWERS OVER THE COASTAL WATERS EAST OF
CAMERON ALONG WITH A NARROW BAND MOVING WEST ACRS THE SABINE
RIVER. SHOWER CHCS SHOULD DIMINISH ACRS ERN PORTIONS OF THE AREA
TONIGHT...WITH A SLT TO LOW END CHC EXPECTED MAINLY ALONG AND WEST
OF A LINE FROM LEESVILLE TO LAKE CHARLES. ADJUSTED POP/WX GRIDS
SLIGHTLY TO INCORPORATE RECENT HRRR GUIDANCE. ALSO TWEAKED HOURLY
WINDS AS WELL AS TEMP AND DEWPOINT GRIDS...ACCOUNTING FOR RECENT
OBSERVATIONS. REMAINDER OF FCST IS IN OTHERWISE DECENT SHAPE AND
UPDATES HAVE BEEN SENT. 24
PREV DISCUSSION... /ISSUED 706 PM CDT MON MAY 4 2015/
DISCUSSION...
05/00Z TAF ISSUANCE.
AVIATION...
ISLTD SHRA/TSRA AND BKN VFR CIGS ACCOMPANY A WEAK INVERTED TROF
CROSSING SRN LA AND THE NRN GULF OF MEXICO. THIS TROF WILL CROSS
THE REGION TONIGHT INTO TUESDAY MORNING...WITH THE MAIN AXIS OF
CLOUDS/SHRA SHIFTING WEST. ACTIVITY EXPECTED TO DIMINISH THIS
EVENING THEN INCREASE LATE TONIGHT...MAINLY NEAR LCH/BPT...AS
SHOWERS OR STORMS MOVE INLAND OFF THE GULF. OTHERWISE...EXPECT VFR
CONDITIONS TO PREVAIL THROUGH THE PERIOD AT LFT/ARA/AEX WITH MVFR
CIGS DEVELOPING AT LCH/BPT AFTER MIDNIGHT. SELY WINDS 5-10 KT
TONIGHT WILL STRENGTHEN 10-15 KT TUESDAY MORNING WITH GUSTS TO 25
KT AT TIMES DURING THE DAY. 24
PREV DISCUSSION... /ISSUED 350 PM CDT MON MAY 4 2015/
DISCUSSION...
NORTH-SOUTH ORIENTED INVERTED SFC TROF...OR EASTERLY
WAVE...STRETCHES ROUGHLY ALONG THE ATCHAFALAYA RIVER AND ON OUT
INTO THE CENTRAL GULF OF MEXICO AS OF 20Z. THIS FEATURE HAS
ASSISTED WITH THE DEVELOPMENT OF ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS OVER PARTS OF SOUTH AND EAST CENTRAL LOUISIANA THIS
AFTERNOON. THE WAVE IS PROGGED TO CONTINUE WWD TONIGHT...WITH A
GENERAL DECREASE IN BOTH COVERAGE AND INTENSITY OF CONVECTION EXPECTED
THIS EVENING WITH THE LOSS OF DIURNAL INSTABILITY. AN UPTICK IS
LIKELY OVER THE GULF WATERS AFTER MIDNIGHT AND TWD THE EARLY
MORNING HRS WITH THE MARINE DMAX...WITH THE NWD CELL MOTION
LEADING TO AT LEAST SOME ACTIVITY SPREADING INLAND.
POPS WERE RAISED OVER EAST TX TOMORROW AS THE WAVE ENTERS A
REGION OF INCREASED UPPER DIVERGENCE AND DEEPER MSTR...WITH
COVERAGE EXPECTED TO EXCEED THAT OBSERVED TODAY.
PATTERN THEREAFTER MARKED BY A SW TO NE RIDGE AXIS OVERHEAD...WITH
A MOIST SOUTHERLY LOW LEVEL FLOW AND SUBTLE IMPULSES EJECTING
AHEAD OF A DIGGING WRN CONUS TROF. LOW END POPS...WITH A GRADIENT
THAT GENERALLY DECREASES FROM WEST TO EAST...ALONG WITH SEASONAL
HIGHS AND ABOVE NORMAL LOWS WILL RESULT.
THE TROF IS PROGGED TO EDGE EASTWARD OVER THE WEEKEND...SLOWLY
ERODING THE RIDGE ALOFT...THEN FINALLY LIFTING OUT INTO THE
CENTRAL CONUS AND FLATTENING IT OUT EARLY NEXT WEEK. GLOBAL MODELS
ALSO PROG A FRONTAL BOUNDARY INTO THE REGION ON SUN NIGHT INTO
MON.
13
MARINE...
WINDS AND SEAS WILL INCREASE TONIGHT INTO TUESDAY AS THE PRESSURE
GRADIENT TIGHTENS WHILE AN EASTERLY WAVE MOVES WEST ACROSS THE
NORTHERN GULF. ELEVATED WINDS AND SEAS WILL CONTINUE INTO
TUESDAY NIGHT...SUBSIDING ON WEDNESDAY AS THE PRESSURE GRADIENT
RELAXES. THE CHANCE OF SHOWERS WILL INCREASE AS THE EASTERLY WAVE
MOVES ACROSS THE REGION TODAY AND TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 63 81 62 83 / 10 10 10 10
LCH 67 80 66 82 / 30 30 10 20
LFT 65 81 64 83 / 10 10 10 20
BPT 68 80 69 82 / 40 50 10 20
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 1 AM CDT WEDNESDAY FOR GMZ452-455-470-
472-475.
SMALL CRAFT EXERCISE CAUTION THROUGH LATE TUESDAY NIGHT FOR
GMZ450.
&&
$$
AVIATION...05
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
447 PM EDT TUE MAY 5 2015
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN WELL OFF THE SOUTHEAST AND MID ATLANTIC
COAST THROUGH TONIGHT...BRINGING VERY WARM AND MAINLY DRY
CONDITIONS TO THE LOCAL AREA. A BACKDOOR COLD FRONT APPROACHES
FROM THE NORTH TONIGHT...THEN DROPS INTO VIRGINIA LATE WEDNESDAY
INTO EARLY THURSDAY...BEFORE DISSIPATING. LOW PRESSURE WILL SPIN
OFF OR NEAR THE SOUTHEAST COAST THURSDAY INTO SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
LATEST ANALYSIS REVEALS SFC HIGH PRESSURE CENTERED WELL OFFSHORE
OF THE VA/NC COAST, EXTENDING BACK ACROSS EASTERN NC. ~1006 MB
LOW PRESSURE WAS ANALYZED ACROSS NEWFOUNDLAND, WITH SFC COLD FRONT
SNAKING BACK ACROSS NEW ENGLAND INTO NE PA/NW NJ AND THE EASTERN
GRT LAKES. A PRE-FRONTAL SFC TROUGH EXTENDS SW FROM SE PA INTO SRN
MD AND NORTHERN VA.
HAVE NOTED SOME INCREASING CU OVER THE PAST FEW HOURS ALONG THE
BLUE RIDGE AND EXPECT TO SEE A BIT MORE TO DEVELOP ACROSS WESTERN
SECTIONS OF THE LOCAL AREA ALONG THE TROUGH BY OVER THE NEXT FEW
HOURS. DO HAVE SOME LOW CHANCES FOR SHOWERS/TSTMS ACRS THE FAR
N/NW LATE THIS AFTN/EVENING. EXPECT ANY SHOWERS TO BE SHORT LIVED
OWING TO FLAT/QUASI-ZONAL FLOW ALOFT AND SHOULD THEREFORE ALLOW
LIMITED CONVECTIVE DEVELOPMENT AND WILL YIELD A VERY SLOW
SOUTHWARD PROGRESSION OF THE FRONT THROUGH TONIGHT AND INTO
TOMORROW.
BY TONIGHT, SHORTWAVE ENERGY NOTED ON IR SAT ACRS THE LWR GRT
LAKES WILL DAMPEN AS IT DIVES SOUTHEAST ACROSS THE NORTHERN MID-
ATLANTIC. RESULTANT UPPER FLOW SHIFTS TO THE WNW, AND WOULD ALLOW
ANY LIGNERING SHOWERS AND STORMS TO CROSS A BIT FARTHER TO THE
SOUTH. GIVEN THE LIMITED ACTIVITY THUS FAR, AND W/ HRRR NOT OVERLY
EXCITED ABOUT ACTIVITY TONIGHT, WILL HANG ON TO A 30-40% RAIN
CHANCE FOR SOME SCT SHRAS THIS EVENING ACROSS THE WEST, AND LATE
TONIGHT/OVERNIGHT FOR THE EASTERN SHORE. FARTHER S-SE, EXPECT DRY
CONDS TO CONTINUE UNDER A PARTLY CLOUDY SKY. LOWS TONIGHT IN THE
UPPER 50S TO LWR 60S.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
HAVE LINGERED A SLIGHT CHC FOR LINGERING SHOWERS JUST AFTER SUNSET
TOMORROW MORNING...W/AREA OF WEAK LIFT SLIDING ESE ALONG AND AHEAD
OF THE BACKDOOR FRONT COINCIDENT WITH PLENTY OF LINGERING LLVL
MOISTURE. ANY SHOWERS WOULD BE BRIEF AND WIDELY SCT AT MOST.
OTHERWISE...DRY IN THE MORNING FOR MOST. EARLY SUN WILL GIVE WAY TO
INCREASING AFTN CLOUDS ACROSS CENTRAL/SOUTHERN ZONES. STRONG HEATING
AND THE ARRIVAL OF THE FRONT WILL LIKELY PROVIDE THE TRIGGER FOR
SOME SCT AFTN SHRAS/THUNDERSTORMS...MAINLY OVR WRN AND NRN COUNTIES
LATE IN THE AFTN INTO WED NIGHT. FOR TEMPS, STILL ON THE WARM SIDE
OF THE GUIDANCE ENVELOPE IN EXPECTATION OF A SLOWER FRONTAL
PROGRESSION...RESULTING IN A PARTLY TO MOSTLY SUNNY SKY EARLY AND
HIGHS FM 80-85 WEST OF THE BAY...TO THE 70S ON THE ERN SHORE. FRONT
BECOMES VERY DIFFUSE TOMORROW NIGHT AND WASHES OUT BY THE TIME IT
REACHES THE VA/NC BORDER. MEANWHILE, SFC LOW PRES WILL BEGIN TO TAKE
SHAPE AND CLOSE OFF ALONG THE EAST COAST OF FLORIDA/SE GA WED
AFTN/NIGHT. WEAK SFC RIDGING WILL RE-ESTABLISH ITSELF OVERHEAD AND
ALLOW FOR A DRY OVERNIGHT WED NIGHT INTO THU MORNING. HOWEVER,
EXPECT A GOOD AMOUNT OF LOW TO MID LEVEL CLOUD TO LINGER OVERNIGHT
INTO THU MORNING ALONG AND BEHIND THE FRONT ACROSS NORTHERN HALF OF
THE AREA. GENERALLY PARTLY SUNNY FARTHER SOUTH A 20-30% CHC FOR A
SHOWER OR TSTM, AGAIN MAINLY IN THE AFTN/EARLY EVENING. E-NE WINDS
WILL RESULT IN HI TEMPS RANGING THRU THE 70S TO NEAR 80 SW TO THE
UPPER 60S/LWR 70S ERN SHORE.
STILL MONITORING THE PROGRESS OF AFOREMENTIONED LOW ALONG THE SE
COAST. MODELS STILL HAVING TROUBLE RESOLVING THIS SYSTEM...WHICH IS
CASTING A BIT OF LOWER CONFIDENCE ON THE HANDLING OF THIS SYSTEM.
THE 12Z/5 GFS CONTINUES TO BRING THE SFC LOW INLAND OF THE SC/NC
COAST...WITH THE 12Z/NAM NOW IN CLOSE ENOUGH TO COVER THU NIGHT AND
FRIDAY. ITS SOLUTION IS SLIGHTLY FASTER THAN THE GFS AND TAKES THE
SURFACE LOW INLAND ACROSS EXTREME NE GA/COASTAL SC BY EARLY FRIDAY
MORNING. FOR ITS PART, THE OPERATIONAL ECMWF REMAINS OFFSHORE, BUT
HAS TRENDED TOWARD THE GFS IN MOVING A BIT CLOSER TO THE COAST WITH
THE SFC LOW...AND EVEN KEEPS THE LOW NEARLY STATIONARY ALONG THE
CAROLINA COAST FOR FRIDAY AND THROUGH THE WEEKEND. HAVE GONE WITH A
GFS WEIGHTED GFS/ECMWF BLEND FOR FRIDAY UNTIL MODELS COME INTO A BIT
CLOSER AGREEMENT. EITEHR WAY, EXPECT FRIDAY TO BE PREDOMINATELY
DRY ACROSS THE LOCAL AREA, BUT SHOULD SEE SOME (MAINLY) DIURNALLY
DRIVEN SCT SHOWERS/TSTMS POSSIBLE OVER THE SOUTHERN HALF OF THE
AREA (BEST CHC SOUTH OF THE BORDER INTO NC). HIGHS 80-85 INLAND,
COOLER U60S TO M70S ALONG THE COAST IN CONTINUED ONSHORE FLOW.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE EXTENDED PERIOD WILL BEGIN WITH LO PRES SPINNING JUST OFF OR
ALNG THE SE OR NC CST FRI NGT INTO MON MORNG. THEN...MODELS SHOW
THE LO WEAKENING AND GETTING PUSHED NNE ALNG OR JUST OFF THE VA
CST MON NGT INTO TUE MORNG...AS A COLD FRONT APPROACHES FM THE W.
THAT FRONT WILL THEN MOVE ACRS THE AREA TUE INTO TUE NGT. WILL
HAVE 20%-30% POPS FOR SHOWERS OR TSTMS OVR MUCH OF THE REGION FRI
NGT THRU MON NGT...DUE TO MOISTURE/LIFT FM THE LO PRES AREA.
THEN...HAVE 30%-40% POPS FOR TUE/TUE NGT ASSOCIATED WITH THE COLD
FRONT. TEMPS WILL BE ABV NORMAL THRU THE PERIOD...WITH HIGHS
RANGING FM THE MID 70S TO MID 80S. LOWS WILL RANGE FM THE UPR 50S
TO MID 60S.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
HIGH PRESSURE GENERALLY IN CONTROL OVER THE MID-ATLANTIC THIS
AFTERNOON WITH A WEAK SURFACE TROUGH TO THE NORTH OF THE AKQ CWA.
A COLD FRONT REMAINS OVER SOUTHERN NY STRETCHING WEST INTO PA AND
OH. SWLY WINDS 10-15 KT CONTINUE WITH A FEW AFTERNOON GUSTS AROUND
20 KT. SHOWERS/THUNDERSTORMS DEVELOP ALONG THE FRONT LATE
TODAY...DROPPING SWD TOWARD THE NRN LOCAL AREA TONIGHT. WILL
LIKELY SEE AN INCREASE IN MID-HIGH CLOUDS EARLY TONIGHT AT KSBY
AND KRIC...WITH SHOWERS (POSSIBLY A THUNDERSTORM) POSSIBLE LATE
TONIGHT AT KSBY.
OUTLOOK: THERE WILL BE A DAILY CHANCE FOR MAINLY AFTN AND EARLY
EVENING SHOWERS AND THUNDERSTORMS WEDNESDAY THROUGH
SATURDAY. THEY ARE NOT EXPECTED TO BE WIDESPREAD. OTHERWISE
MAINLY VFR CONDITIONS ARE EXPECTED DURING THE PERIOD. LATE IN THE
WEEK...PATCHY FOG WILL BE PSBL AROUND SUNRISE.
&&
.MARINE...
NO HEADLINES IN THE SHORT TERM TNGT THRU THU. HI PRES WILL SLIDE
FARTHER OUT TO SEA TNGT THRU WED. MODELS STILL SHOW LO PRES
SPINNING JUST OFF OR NEAR THE SE CST THU INTO SUN. EXPECT SSW
WINDS 15 KT OR LESS TNGT INTO WED NGT...THEN E OR SE WINDS 5 TO 15
KT THU INTO SUN. WAVES WILL BE 1 TO 2 FT...AND SEAS WILL BE 2 TO 4
FT.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...LKB/MAM
LONG TERM...TMG
AVIATION...DAP
MARINE...TMG
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
335 PM EDT TUE MAY 5 2015
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN WELL OFF THE SOUTHEAST AND MID ATLANTIC
COAST THROUGH TONIGHT...BRINGING VERY WARM AND MAINLY DRY
CONDITIONS TO THE LOCAL AREA. A BACKDOOR COLD FRONT APPROACHES
FROM THE NORTH TONIGHT...THEN DROPS INTO VIRGINIA LATE WEDNESDAY
INTO EARLY THURSDAY...BEFORE DISSIPATING. LOW PRESSURE WILL SPIN
OFF OR NEAR THE SOUTHEAST COAST THURSDAY INTO SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
LATEST ANALYSIS REVEALS SFC HIGH PRESSURE CENTERED WELL OFFSHORE
OF THE VA/NC COAST, EXTENDING BACK ACROSS EASTERN NC. ~1006 MB
LOW PRESSURE WAS ANALYZED ACROSS NEWFOUNDLAND, WITH SFC COLD FRONT
SNAKING BACK ACROSS NEW ENGLAND INTO NE PA/NW NJ AND THE EASTERN
GRT LAKES. A PRE-FRONTAL SFC TROUGH EXTENDS SW FROM SE PA INTO SRN
MD AND NORTHERN VA.
HAVE NOTED SOME INCREASING CU OVER THE PAST FEW HOURS ALONG THE
BLUE RIDGE AND EXPECT TO SEE A BIT MORE TO DEVELOP ACROSS WESTERN
SECTIONS OF THE LOCAL AREA ALONG THE TROUGH BY OVER THE NEXT FEW
HOURS. DO HAVE SOME LOW CHANCES FOR SHOWERS/TSTMS ACRS THE FAR
N/NW LATE THIS AFTN/EVENING. EXPECT ANY SHOWERS TO BE SHORT LIVED
OWING TO FLAT/QUASI-ZONAL FLOW ALOFT AND SHOULD THEREFORE ALLOW
LIMITED CONVECTIVE DEVELOPMENT AND WILL YIELD A VERY SLOW
SOUTHWARD PROGRESSION OF THE FRONT THROUGH TONIGHT AND INTO
TOMORROW.
BY TONIGHT, SHORTWAVE ENERGY NOTED ON IR SAT ACRS THE LWR GRT
LAKES WILL DAMPEN AS IT DIVES SOUTHEAST ACROSS THE NORTHERN MID-
ATLANTIC. RESULTANT UPPER FLOW SHIFTS TO THE WNW, AND WOULD ALLOW
ANY LIGNERING SHOWERS AND STORMS TO CROSS A BIT FARTHER TO THE
SOUTH. GIVEN THE LIMITED ACTIVITY THUS FAR, AND W/ HRRR NOT OVERLY
EXCITED ABOUT ACTIVITY TONIGHT, WILL HANG ON TO A 30-40% RAIN
CHANCE FOR SOME SCT SHRAS THIS EVENING ACROSS THE WEST, AND LATE
TONIGHT/OVERNIGHT FOR THE EASTERN SHORE. FARTHER S-SE, EXPECT DRY
CONDS TO CONTINUE UNDER A PARTLY CLOUDY SKY. LOWS TONIGHT IN THE
UPPER 50S TO LWR 60S.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
HAVE LINGERED A SLIGHT CHC FOR LINGERING SHOWERS JUST AFTER SUNSET
TOMORROW MORNING...W/AREA OF WEAK LIFT SLIDING ESE ALONG AND AHEAD
OF THE BACKDOOR FRONT COINCIDENT WITH PLENTY OF LINGERING LLVL
MOISTURE. ANY SHOWERS WOULD BE BRIEF AND WIDELY SCT AT MOST.
OTHERWISE...DRY IN THE MORNING FOR MOST. EARLY SUN WILL GIVE WAY TO
INCREASING AFTN CLOUDS ACROSS CENTRAL/SOUTHERN ZONES. STRONG HEATING
AND THE ARRIVAL OF THE FRONT WILL LIKELY PROVIDE THE TRIGGER FOR
SOME SCT AFTN SHRAS/THUNDERSTORMS...MAINLY OVR WRN AND NRN COUNTIES
LATE IN THE AFTN INTO WED NIGHT. FOR TEMPS, STILL ON THE WARM SIDE
OF THE GUIDANCE ENVELOPE IN EXPECTATION OF A SLOWER FRONTAL
PROGRESSION...RESULTING IN A PARTLY TO MOSTLY SUNNY SKY EARLY AND
HIGHS FM 80-85 WEST OF THE BAY...TO THE 70S ON THE ERN SHORE. FRONT
BECOMES VERY DIFFUSE TOMORROW NIGHT AND WASHES OUT BY THE TIME IT
REACHES THE VA/NC BORDER. MEANWHILE, SFC LOW PRES WILL BEGIN TO TAKE
SHAPE AND CLOSE OFF ALONG THE EAST COAST OF FLORIDA/SE GA WED
AFTN/NIGHT. WEAK SFC RIDGING WILL RE-ESTABLISH ITSELF OVERHEAD AND
ALLOW FOR A DRY OVERNIGHT WED NIGHT INTO THU MORNING. HOWEVER,
EXPECT A GOOD AMOUNT OF LOW TO MID LEVEL CLOUD TO LINGER OVERNIGHT
INTO THU MORNING ALONG AND BEHIND THE FRONT ACROSS NORTHERN HALF OF
THE AREA. GENERALLY PARTLY SUNNY FARTHER SOUTH A 20-30% CHC FOR A
SHOWER OR TSTM, AGAIN MAINLY IN THE AFTN/EARLY EVENING. E-NE WINDS
WILL RESULT IN HI TEMPS RANGING THRU THE 70S TO NEAR 80 SW TO THE
UPPER 60S/LWR 70S ERN SHORE.
STILL MONITORING THE PROGRESS OF AFOREMENTIONED LOW ALONG THE SE
COAST. MODELS STILL HAVING TROUBLE RESOLVING THIS SYSTEM...WHICH IS
CASTING A BIT OF LOWER CONFIDENCE ON THE HANDLING OF THIS SYSTEM.
THE 12Z/5 GFS CONTINUES TO BRING THE SFC LOW INLAND OF THE SC/NC
COAST...WITH THE 12Z/NAM NOW IN CLOSE ENOUGH TO COVER THU NIGHT AND
FRIDAY. ITS SOLUTION IS SLIGHTLY FASTER THAN THE GFS AND TAKES THE
SURFACE LOW INLAND ACROSS EXTREME NE GA/COASTAL SC BY EARLY FRIDAY
MORNING. FOR ITS PART, THE OPERATIONAL ECMWF REMAINS OFFSHORE, BUT
HAS TRENDED TOWARD THE GFS IN MOVING A BIT CLOSER TO THE COAST WITH
THE SFC LOW...AND EVEN KEEPS THE LOW NEARLY STATIONARY ALONG THE
CAROLINA COAST FOR FRIDAY AND THROUGH THE WEEKEND. HAVE GONE WITH A
GFS WEIGHTED GFS/ECMWF BLEND FOR FRIDAY UNTIL MODELS COME INTO A BIT
CLOSER AGREEMENT. EITEHR WAY, EXPECT FRIDAY TO BE PREDOMINATELY
DRY ACROSS THE LOCAL AREA, BUT SHOULD SEE SOME (MAINLY) DIURNALLY
DRIVEN SCT SHOWERS/TSTMS POSSIBLE OVER THE SOUTHERN HALF OF THE
AREA (BEST CHC SOUTH OF THE BORDER INTO NC). HIGHS 80-85 INLAND,
COOLER U60S TO M70S ALONG THE COAST IN CONTINUED ONSHORE FLOW.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MEDIUM RANGE PERIOD HIGHLY DEPENDENT PERSISTENT UPPER RIDGE OVER THE
EAST, AS WELL AS THE DEVELOPMENT AND EVENTUAL PROGRESS OF EXPECTED
DEVELOPMENT OF AN AREA OF LOW PRESSURE OFF THE EAST COAST OF
FLORIDA. MODELS ARE IN GENERAL AGREEMENT OF THE DEVELOPMENT AND
INITIAL SLOW DRIFT NORTHWARD ON WEDNESDAY. THE HURRICANE CENTER IS
CONTINUING TO MONITOR THIS FEATURE FOR POTENTIAL SUBTROPICAL
DEVELOPMENT. SFC RIDGING TO THE NORTH AND W-NW FLOW ALOFT SHOULD
FORCE THE LOW TO MEANDER AROUND A POSITION ALONG/JUST OFF THE
SOUTHEAST COAST THROUGH THE WEEKEND. THE GEFS AND EURO ENSEMBLES
BOTH CONTINUE TO TAKE THE LOW INLAND ALONG THE SC/GA COAST, AS DOES
THE NEW 12Z/04 GFS. THE OPERATIONAL EUROPEAN, MEANWHILE CONTINUES TO
KEEP THE SYSTEM OFFSHORE. A SOLUTION TOWARDS THE GFS REMAINS THE HPC
PREFERENCE, AND HV EDGED THE FORECAST IN THIS DIRECTION. THIS
SCENARIO WOULD YIELD SLIGHT CHC TO LOW CHC POP FOR MAINLY DIURNALLY
DRIVEN SHOWERS/T-STORMS AT MOST ACROSS OUR AREA. LOWEST CHANCES WILL
BE ACROSS THE NORTH WITH SFC RIDGING IN PLACE NORTH OF THE AREA.
OTHER HEADLINE FOR THE PERIOD WILL BE THE WARMER TEMPERATURES.
E-SE FLOW WILL BRING A MODEST INCREASE IN HUMIDITY, AND INCREASING
LOW LEVEL THICKNESSES FAVOR WARM HIGHS IN THE 80S UNDER A PARTLY
TO MOSTLY SUNNY SKY. EARLY MORNING LOWS LOOK TO REMAIN WELL INTO
THE 50S TO MID 60S LATE WEEK INTO EARLY NEXT WEEK.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
HIGH PRESSURE GENERALLY IN CONTROL OVER THE MID-ATLANTIC THIS
AFTERNOON WITH A WEAK SURFACE TROUGH TO THE NORTH OF THE AKQ CWA.
A COLD FRONT REMAINS OVER SOUTHERN NY STRETCHING WEST INTO PA AND
OH. SWLY WINDS 10-15 KT CONTINUE WITH A FEW AFTERNOON GUSTS AROUND
20 KT. SHOWERS/THUNDERSTORMS DEVELOP ALONG THE FRONT LATE
TODAY...DROPPING SWD TOWARD THE NRN LOCAL AREA TONIGHT. WILL
LIKELY SEE AN INCREASE IN MID-HIGH CLOUDS EARLY TONIGHT AT KSBY
AND KRIC...WITH SHOWERS (POSSIBLY A THUNDERSTORM) POSSIBLE LATE
TONIGHT AT KSBY.
OUTLOOK: THERE WILL BE A DAILY CHANCE FOR MAINLY AFTN AND EARLY
EVENING SHOWERS AND THUNDERSTORMS WEDNESDAY THROUGH
SATURDAY. THEY ARE NOT EXPECTED TO BE WIDESPREAD. OTHERWISE
MAINLY VFR CONDITIONS ARE EXPECTED DURING THE PERIOD. LATE IN THE
WEEK...PATCHY FOG WILL BE PSBL AROUND SUNRISE.
&&
.MARINE...
LATEST WEATHER ANALYSIS ACROSS THE WATERS DEPICTS HIGH PRESSURE
CENTERED ROUGHLY 500 NM OFF THE MID ATLANTIC COAST AND LOW PRESSURE
OVER NEWFOUNDLAND. AN ATTENDANT COLD FRONT EXTENDS FROM THE SFC LOW
SWWD INTO NEW ENGLAND AND THE OH VALLEY. GRADIENT HAS RESULTED IN A
PERIOD OF MARGINAL SCA CONDITIONS OVER THE BAY AND LOWER JAMES RIVER
EARLY THIS MORNING...WITH OCCASIONAL GUSTS 20-25 KT. HAVE OPTED TO
ISSUE SCA HEADLINES THRU 7 AM AS GRADIENT EXPECTED TO RELAX AND LOW
LEVELS STABILIZE. WAVES GENERALLY 2-3 FT AND SEAS AROUND 3 FT. HIGH
PRESSURE PUSHES FARTHER OFFSHORE TODAY AS THE COLD FRONT SLOWLY
APPROACHES FROM THE NORTH. S-SW WINDS GENERALLY 10-15 KT
TODAY...WITH OCCASIONAL GUSTS TO 20 KT IN THE COASTAL WATERS. SLIGHT
UPTICK IN WINDS POSSIBLE AGAIN TONIGHT...BUT NOT AS STRONG AS EARLY
THIS MORNING AS THE WINDS ALOFT ARE PROGGED TO BE WEAKER. THE COLD
FRONT IS PROGGED TO REACH THE NRN WATERS LATE WEDS...DROPPING ACROSS
THE WATERS WEDS NIGHT INTO THURS. THE FRONT THEN WASHES OUT OVER THE
REGION THURS AS LOW PRESSURE LOCATES OFF THE SE COAST. FLOW BEHIND
THE FRONT BECOMES NELY...REMAINING AOB 15 KT. SEAS ONLY PROGGED TO
BUILD TO 3-4 FT WEDS NIGHT-THURS. UNCERTAINTY STILL EXISTS IN THE
EXACT TRACK AND STRENGTH OF THE COASTAL LOW LATE IN THE WEEK.
ATTM...MODELS KEEP THE LOW OFF THE SE COAST INTO THE WEEKEND. THIS
TRACK STAYS TOO FAR SOUTH TO BRING ANY SIGNIFICANT INCREASE IN SEAS
AND WINDS TO THE LOCAL AREA. OTHERWISE...HIGH PRESSURE REMAINS OVER
THE LOCAL WATERS THRU THE WEEKEND WITH SE WINDS GENERALLY AOB 15 KT.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...LKB/MAM
LONG TERM...MAM
AVIATION...SAM/DAP
MARINE...MAM/SAM
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
627 AM EDT TUE MAY 5 2015
.SYNOPSIS...
A SLOW MOVING FRONTAL BOUNDARY WILL KEEP RAIN CHANCES IN THE
FORECAST THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
CURRENT RADAR IMAGERY SHOWS A MASS OF SHOWERS CONGEALING OVER
EASTERN OHIO...PUSHING SLOWLY TO THE EAST. THIS ACTIVITY IS
LOCATED ALONG AND JUST SOUTH OF THE CURRENT WEAK SURFACE
FRONT...ORIENTED WITH HIGHER MOISTURE CONTENT. EXPECTING THESE
SHOWERS TO REACH THE PITTSBURGH METRO WITHIN THE NEXT TWO HOURS
BRINGING LIGHT RAIN FOR THE MORNING COMMUTE. HRRR HAS HAD A GOOD
HANDLE ON THIS REMNANT SHOWER ACTIVITY OVER THE LAST SEVERAL
HOURS...AND THUS WAS FOLLOWED THROUGH MID-MORNING.
BROAD FRONTAL ZONE AND DEEPER MOISTURE WILL SHIFT NORTH SOME
THROUGH MIDDAY AS A WAVE CURRENTLY NEARING LAKE MICHIGAN TRACKS
THROUGH THE SOUTHERN GREAT LAKES. THIS WILL SHIFT THE FOCUS OF
ANY AFTERNOON SHOWER OR THUNDERSTORM ACTIVITY NORTH AS WELL. HI-
RES MODELS THAT ARE HANDLING THE CURRENT TRENDS WITH SOME
SUCCESS...HAVE BEEN LESS THAN EXCITED ABOUT CONVECTIVE
DEVELOPMENT THIS AFTERNOON...TO THE POINT OF VERY LITTLE
PRECIPITATION ACROSS THE FORECAST AREA. STILL THINKING MODELS ARE
UNDERPRODUCING...GIVEN THE AVAILABILITY OF MOISTURE AND THE AT
LEAST MARGINAL INSTABILITY NOTED IN THE AFTERNOON SOUNDINGS. WILL
MAINTAIN CHANCE TO LIKELY POPS NORTH OF PITTSBURGH.
MODEL GUIDANCE HAS TRENDED FURTHER NORTH WITH THE TRACK OF THE
UPPER-LEVEL WAVE TONIGHT...AS THE RIDGE OF HIGH PRESSURE RE-BUILDS
IN THE MID-WEST. MODIFICATIONS WERE MADE TO PUSH TONIGHTS RAIN
CHANCES WELL NORTH OF PREVIOUS FORECAST. SOME OF OUR SOUTHERN AND
WESTERN ZONES SHOULD EVEN GET SOME CLEARING HEADING INTO TONIGHT
WITH THE FOCUS OF DEEPER MOISTURE SHIFTING NORTH.
TAX
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
RIDGING STARTS TO BUILD OVER THE OHIO VALLEY DURING THE DAY ON
WEDNESDAY. THIS WILL DROP H500 HEIGHTS ACROSS THE CWA IN RESPONSE
AND HELP TO SAG THE FRONTAL BOUNDARY A BIT FURTHER SOUTH DURING
THE DAY. FOCUSED HIGHER POPS IN SOUTHERN PORTIONS OF CWA DURING
THE AFTERNOON. ENOUGH INSTABILITY IS PRESENT FOR THE CONTINUED
CHANCE OF THUNDER AS WELL. KEPT POPS IN CHANCE CATEGORY WITH
CONTINUED UNCERTAINTY AS TO FRONTAL EVOLUTION. AS RIDGE STARTS TO
BUILD EASTWARD...FRONTAL BOUNDARY WILL BECOME MORE DIFFUSE WITH
TIME. ALLOW POPS TO FALL OFF DURING THE EVENING HOURS WITH LOSS OF
HEATING.
H500 RIDGE IS IN CONTROL FOR THE REMAINDER OF THIS PERIOD...WITH
THE RIDGE AXIS PASSING BY AROUND 00Z FRIDAY. GFS/ECMWF BOTH PAINT
SOME DIURNAL QPF ACROSS THE AREA THURSDAY AND FRIDAY AFTERNOONS.
THINK THAT THIS IS OVERDONE FOR THE MOST PART AS AT LEAST MODEST
CAPPING SHOULD BE PRESENT UNDER THE RIDGE. EXCEPTION COULD BE
ALONG THE EASTERN RIDGES WITH MODEST UPSLOPE FLOW...AND KEPT AN
AFTERNOON/EVENING SLIGHT CHANCE BOTH AFTERNOONS IN THIS AREA.
OTHERWISE...DRY AND WARM CONDITIONS WILL PERSIST. A SLOW WARMING
TREND WILL SEE TEMPERATURES RISE BACK INTO THE LOWER AND MID 80S
FOR MOST AREAS BY FRIDAY.
CL
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
UPPER RIDGE GETS SLOWLY DISLODGED WITH TIME AS ENERGY EJECTS FROM
WESTERN U.S. TROUGH AND TOWARDS THE UPPER MISSISSIPPI VALLEY BY
00Z MONDAY. RESULTING SURFACE LOW AND FRONTAL SYSTEM WILL ADVANCE
EASTWARD WITH TIME...PERHAPS ARRIVING MONDAY NIGHT OR TUESDAY.
AHEAD OF THIS...MAINLY DIURNAL POPS GET A BIT HIGHER EACH DAY
WITH THE DEPARTURE OF THE RIDGE. RIPPLES ALONG THE BACK SIDE OF
THE RIDGE MAY PROVIDE LOCALIZED ENHANCEMENT...WHICH OF COURSE ARE
TOUGH TO TIME AT THIS DISTANCE. THE FRONT BRINGS MORE GENERALIZED
PRECIPITATION CHANCES MONDAY INTO TUESDAY.
FAIRLY STATIC ABOVE NORMAL TEMPERATURES ARE FORECAST FRIDAY NIGHT
THROUGH MONDAY NIGHT...WITH HIGHS IN THE 80S AND LOWS ON EITHER
SIDE OF 60. COOLER TEMPERATURES MAY ARRIVE TUESDAY WITH THE FRONT.
CL
&&
.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
VISIBILITY RESTRICTIONS THIS MORNING HAVE BEEN CONFINED TO A
SELECT FEW TERMINALS WHERE AT LEAST SOME CLEARING HAD TAKEN
PLACE...AND FOG WAS ABLE TO FORM. ANY REMAINING RESTRICTIONS
DUE TO FOG SHOULD END QUICKLY AFTER SUNRISE WITH MIXING AND AS A
BROADER CLOUD SHIELD MOVES IN.
ADDITIONALLY...AN AREA OF SHOWERS IS MOVING ALONG THE BROAD
FRONTAL ZONE...AND ARE CURRENTLY THROUGH EASTERN OHIO. NOT
EXPECTING MUCH FURTHER EXPANSION OR STRENGTHENING OF THESE
SHOWERS THROUGH MID-MORNING...BUT THEY COULD BRING TEMPORARY
VISIBILITY RESTRICTIONS AS THEY SLOWLY MOVE EAST ACROSS
HLG/BVI/PIT/AGC.
LATER TODAY...HAVE THIS LINE OF SHOWERS LIFTING NORTH WITH THE
BROAD FRONTAL ZONE WHERE INSTABILITY THIS AFTERNOON COULD DRIVE
ADDITIONAL SHOWERS/THUNDERSTORMS. HAVE INCLUDED VCTS FOR NORTHERN
AND EASTERN TAF SITES...BUT SPATIAL EXTENT OF THUNDERSTORM
ACTIVITY SHOULD BE FAIRLY LIMITED.
TAX
.OUTLOOK.../TUESDAY NIGHT THROUGH SATURDAY/...
SCATTERED RESTRICTIONS IS A POSSIBILITY EARLY WEDNESDAY AS
FRONTAL BOUNDARY SLOWLY DECAYS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
154 PM EDT TUE MAY 5 2015
.AVIATION...
THE MATURE MCS AND INITIAL SURGE OF DEEP MOISTURE IS CURRENTLY
TRACKING THROUGH SOUTHEASTERN MICHIGAN THIS AFTERNOON. LATEST DATA
SUGGESTS A CONTINUED POTENTIAL FOR SHOWERS AND THUNDERSTORMS OVER
MUCH OF THE AREA THROUGH AT LEAST THE EARLY EVENING HOURS. A
DEVELOPING WARM FRONT IS THEN EXPECTED TO SLOWLY ORGANIZE OVER
SECTIONS OF SEMICH TONIGHT. UNCERTAINTY EXISTS TO EXACTLY WHERE THIS
BOUNDARY WILL STALL OUT FOR A TIME...BUT LATEST INDICATIONS ARE
SUGGESTING THE NORTHERN DETROIT METRO AREA THROUGH THE I 69 CORRDOR.
IT IS ALONG THIS BOUNDARY THAT A POTENTIAL EXISTS FOR
CONTINUED...LONG DURATION RAIN OVERNIGHT. FOCUSED THIS RAIN MENTION
AT THE KPTK/KFNT FOR THIS TAF ISSUANCE...WILL CONTINUE TO MONITOR
THE NEED FOR THE SOUTHERN TAF SITES. THE OTHER IMPORTANT ISSUE FOR
TONIGHT WILL BE THE POTENTIAL FOR IFR/LIFR CIGS ALONG AND TO THE
SOUTH OF THE DEVELOPING FRONTAL BOUNDARY. WENT MORE AGGRESSIVE WITH
IFR/LIFR CIGS SOUTH.
FOR DTW...RAIN POTENTIAL WILL NOW SHIFT TO MORE SHOWER CHARACTER AS
THE INITIAL MATURE MCS SHIFTS NORTHWARD THROUGH THE CWA. WILL NEED
TO MONITOR PORTIONS OF NORTHERN ILLINOIS/INDIANA WHERE ADDITIONAL
SHOWER AND THUNDERSTORM DEVELOPMENT IS FORECASTED TO TAKE PLACE. IT
REMAINS POSSIBLE THIS ACTIVITY WHILE MOVING EASTWARD COULD IMPACT
PORTIONS OF FAR SOUTHERN MICHIGAN...INCLUDING THE METRO TERMINAL.
OTHERWISE TONIGHT...EXPECTATIONS AT THIS TIME ARE FOR THE WARM FRONT
TO SET UP NORTH OF THE TERMINAL...FOCUSING BEST LONG DURATION RAINS
CHANCES NORTH. LIFR CIGS TONIGHT AND TOMORROW MORNING.
//DTW THRESHOLD PROBABILITIES...
* HIGH FOR CEILING BELOW 5000 FT TONIGHT.
* LOW FOR THUNDERSTORMS THIS EVENING AND TONIGHT
* LOW FOR CIGS TO FALL BELOW 200 FEET.
&&
.PREV DISCUSSION...ISSUED 1034 AM EDT TUE MAY 5 2015
UPDATE...
THE DETAILED FORECAST REASONING PROVIDED IN THE EARLY MORNING
DISCUSSION WAS WELL DONE AND REMAINS VALID.
A MATURE MCS AND COMPLEX OF SHORTWAVE ENERGY SUPPORTED BY RIGHT
ENTRANCE REGION DYNAMICS ALOFT IS CURRENTLY LIFTING INTO
SOUTHEASTERN MICHIGAN THIS MORNING. SURFACE PRECIPITATION REPORTS
SUPPORT LIGHT TO MODERATE RAIN OCCURRING WITHIN THE
FORWARD...WARM AIR ADVECTION QUADRANTS OF THE MCS. WITH THE RAIN
MOVING IN...SOUTHEASTERN MICHIGAN CAN EXPECT CATEGORICAL/PERIODS
OF RAIN THROUGHOUT THE AFTERNOON HOURS. FORECAST UNCERTAINTY FOR
THE SHORT TERM PERIOD CENTERS ON WHEN EXACTLY SYNOPTIC
SUPPORT/RAIN WILL END OVER THE AREA. LATEST NAM AND RAP ARE REALLY
PAINTING DIFFERENT PICTURES. NAM SUGGESTS SUBSIDENCE IN THE WAKE
OF THIS MCS...MAY BRING A QUIET PERIOD EARLY THIS EVENING...WHILE
THE RAP DRAGS OUT THE DURATION OF THIS CATEGORICAL RAIN INTO THE
EVENING. THERE REMAINS A WINDOW OF OPPORTUNITY FOR SOME THUNDER
CHANCES LATE THIS AFTERNOON...POST 20Z. THOSE CHANCES APPEAR TO
HINGE ON THE LIKELIHOOD OF THE NAM SOLUTION VERIFYING. NEGLIGIBLE
CONVECTIVE INSTABILITY YIELDS NO SUPPORT FOR SEVERE THUNDERSTORM
POTENTIAL.
PREV DISCUSSION...ISSUED 355 AM EDT TUE MAY 5 2015
SHORT TERM... TODAY AND TONIGHT
A WET 24 HOUR PERIOD IS SETTING UP OVER SOUTHERN LOWER MICHIGAN
TODAY THROUGH TONIGHT. THE TRI CITIES AND NORTHERN THUMB MAY ESCAPE
THE BULK OF THE RAINFALL TODAY BUT THE REST OF SE MICHIGAN STANDS TO
PICK UP A PROLONGED PERIOD OF SHOWERS AND THUNDERSTORMS. THE SURFACE
FRONT WILL REMAIN SOUTH OF THE OHIO BORDER THROUGH THE PERIOD SO
THUNDERSTORMS WILL BE THE ELEVATED VARIETY AND MAINLY CONTRIBUTE TO
LOCALLY HEAVY DOWNPOURS. RAINFALL TOTALS LOCALLY AROUND 1 INCH WILL
BE POSSIBLE BY SUNRISE WEDNESDAY.
WIDESPREAD SHOWERS AND THUNDERSTORMS ARE ALREADY UNDERWAY OVER THE
MIDWEST AND WILL SPREAD TO THE NORTH AND EAST DURING THE REST OF THE
MORNING. THIS AREA OF CONVECTION ORIGINATED ALONG THE FRONT OVER THE
CENTRAL PLAINS DURING PEAK HEATING YESTERDAY AND HAS SINCE GROWN
LARGE ENOUGH AND PERSISTENT ENOUGH TO SUPPORT MCV DEVELOPMENT ALOFT
AND AN AREA OF SURFACE PRESSURE FALLS OVER IOWA AND MISSOURI. THE
WAVE IS JUST STRONG ENOUGH TO SUPPORT A WEAK LOW LEVEL JET FUELING
ACTIVITY OVER NORTHERN ILLINOIS WHICH WILL CONTINUE TO DEVELOP INTO
SOUTHERN LOWER MICHIGAN AS THE LOW TO MID LEVELS OF THE FRONT
STRENGTHEN WITH TIME. CONVECTIVE DEBRIS IN SATELLITE IMAGERY SHOWS
THE ENTRANCE REGION OF A 120 KNOT UPPER JET ANALYZED IN MODEL DATA
AT 250 MB. THIS FEATURE IS POSITIONED FAVORABLY OVER THE GREAT LAKES
TO GENERATE STRONG FRONTOGENESIS THROUGH TODAY WHILE THE LARGE SCALE
FRONTAL POSITION REMAINS STATIONARY AND THEN DRIFTS SLOWLY NORTHWARD
TONIGHT. CROSS SECTIONS OF MODEL DATA FROM THE POSITION OF THE
SURFACE FRONT EXTENDING NORTHWARD TO THE UPPER JET AXIS SHOW THE
STEEPEST PORTION OF THE AGEOSTROPHIC CIRCULATION SETTING UP THROUGH
CENTRAL SECTIONS OF OUR AREA BY AFTERNOON THROUGH THIS EVENING. DEEP
CONVECTIVE INSTABILITY ABOVE THE FRONTAL SURFACE COMBINED WITH
PRECIPITABLE WATER RISING TO ABOUT 1.25 INCHES WILL ENSURE
WIDESPREAD COVERAGE OF SHOWERS WITH EMBEDDED THUNDERSTORMS. LOCALLY
HEAVY RAINFALL WILL ALSO BE POSSIBLE DUE TO THE PERSISTENCE OF THIS
TEXTBOOK UPPER JET ENHANCED FRONTAL CIRCULATION AND THE CONVECTIVE
NATURE OF THE PRECIPITATION PATTERN. SO THEN WHAT COULD GO WRONG IN
THIS FORECAST? THE POTENTIAL FOR SURFACE BASED CONVECTION OVER
INDIANA AND OHIO...COMBINED WITH THE TENDENCY FOR ELEVATED
INSTABILITY TO BECOME LESS EFFECTIVE DURING THE DAY...COULD LEAD TO
A WEAKENING TREND IN THE PATTERN OVER SE MICHIGAN DURING THE
AFTERNOON INTO THIS EVENING. SHOULD THIS OCCUR...IT WOULD DO MORE TO
REDUCE THE POTENTIAL FOR HEAVY RAINFALL IN OUR AREA AND POSSIBLY
ALTER THE LOCATION OF THE MOST PERSISTENT SHOWERS AND OVERALL QPF...
BUT MOST AREAS WILL SEE A LENGTHY PERIOD OF RAIN AS THE MORNING RAMP
UP WOULD CARRY OVER INTO THE AFTERNOON JUST BASED ON INERTIA.
PROGRESSION OF THE UPPER LEVEL RIDGE AND THE ENTRANCE REGION OF THE
UPPER JET WILL NUDGE THE MID LEVEL FRONTAL ZONE TO THE NORTH AND
EAST OVERNIGHT. THIS WILL BRING THE TRI CITIES AND NORTHERN THUMB
MORE INTO THE PATTERN OF REMAINING SHOWERS AND WILL BE THE FAVORED
LOCATION FOR ANY NOCTURNAL REDEVELOPMENT. THE AXIS OF LIKELY POPS
OVER SE MICHIGAN IS PLACED ALONG THE 850 MB THETA-E GRADIENT WHICH
IS WELL AGREED UPON BY THE 00Z MODEL CYCLE AND IS THE MOST FAVORED
LOCATION FOR RENEWED DEVELOPMENT OF NOCTURNAL ELEVATED INSTABILITY
AND SUPPORT FOR SHOWERS THROUGH SUNRISE WEDNESDAY.
LONG TERM...WEDNESDAY THROUGH MONDAY
SE MICHIGAN WILL RESIDE ALONG THE IMMEDIATE DOWNSTREAM SIDE OF AN
ELONGATING UPPER RIDGE ON WEDNESDAY. THE RESULTING WEAKLY SHEARED
WEST-NORTHWEST FLOW WILL SUSTAIN A PERTURBED 850-925 MB FRONTAL ZONE
ACROSS THE REGION. MODELS TRENDING SLIGHTLY STRONGER WITH THE
ASCENT/CONVERGENCE THROUGH THIS LAYER...SUGGESTING THE EXISTING
FRONTAL SLOPE WILL POTENTIALLY BE MORE ACTIVE. THIS WILL SUPPORT
THE INCLUSION OF A LOWER END POP. GREATER POTENTIAL FOR SHOWER
PRODUCTION DURING THE MORNING PERIOD...BEFORE BOTH THE MOISTURE
QUALITY AND AVAILABLE FORCING DIMINISHES AS THE INBOUND UPPER RIDGE
MAKES BETTER INROADS. SUBSTANTIAL CLOUD COVER WITHIN PERSISTENT LOW
LEVEL EASTERLY FLOW WILL CAP THE DIURNAL TEMPERATURE RESPONSE TO
SOME DEGREE...REGARDLESS OF SHOWER COVERAGE. ABSENT OF A LARGER AND
PERSISTENT COVERAGE OF SHOWERS TO DISRUPT THE HEATING CYCLE...
EXISTING THERMAL PROFILE WILL SUPPORT HIGHS GENERALLY WITHIN THE MID
AND UPPER 60S RANGE.
UPPER RIDGE STEADILY BUILDS INTO LOWER MICHIGAN WEDNESDAY NIGHT...
580 DM AT 500 MB MARKING THE RIDGE AXIS CENTERING OVERHEAD BY EARLY
THURSDAY MORNING. THIS PROGRESSION WILL SEND SE MICHIGAN INTO THE
WARM SECTOR BY THURSDAY...SOLID DEPTH TO THE EMERGING SOUTHWEST FLOW
CONTINUING TO POINT TOWARD HIGHS MAKING A RUN INTO THE LOWER 80S.
DRY/STABLE PROFILE STILL INFLUENCED BY EXITING UPPER RIDGING WILL
RESULT IN LITTLE MORE THAN A STANDARD DIURNAL CU FIELD.
CLOSED LOW CURRENTLY PARKED OVER THE DESERT SOUTHWEST WILL LIFT
NORTHEAST THROUGH THE LATTER HALF OF THE WEEK...EVENTUALLY SHEARING
OVER THE TOP OF THE UPPER RIDGE STAGNATING ALONG THE EAST COAST.
THIS LOWERING HEIGHT FIELD WILL BEGIN TO EASE AN ATTENDANT FRONTAL
BOUNDARY EASTWARD WITHIN THE FRIDAY AND SATURDAY WINDOW. GENERAL
TIMING ACROSS THE MODEL SPECTRUM SUGGESTS FRIDAY WILL REMAIN
CHARACTERED BY THE PRE-FRONTAL WARM SECTOR...WITH ANY POSSIBLE LATE
DAY/EVENING CONVECTIVE CHANCES ARRIVING TOO LATE TO DISRUPT ANOTHER
DAY WITH HIGHS IN THE 80S. POTENTIAL IS THERE FOR AN ACTIVE PERIOD
HEADING INTO THE UPCOMING WEEKEND...FRONTAL BOUNDARY EVENTUALLY
ALIGNING OVER OR NEAR THE REGION FOR AN EXTENDED TIME AS THE AXIS
BECOMES PARALLEL TO THE MEAN FLOW. THIS PATTERN WOULD SHAVE A FEW
DEGREE OFF PROSPECTIVE HIGHS THIS WEEKEND RELATIVE TO THE
THU/FRI WARMTH...STILL NEAR TO ABOVE NORMAL THROUGH THIS TIME.
MARINE...
SHOWERY CONDITIONS WITH THE CHANCE OF THUNDERSTORMS WILL EXIST UNDER
PERSIST EAST TO NORTHEAST FLOW OVER THE SOUTHERN LAKE HURON BASIN
AND POINTS SOUTHWARD THROUGH TONIGHT. FAVORABLE MARINE CONDITIONS
ACROSS NORTHERN LAKE HURON DURING THIS TIME AS HIGH PRESSURE BUILDS
INTO THE REGION. MODEST WAVE AND WIND CONDITIONS THROUGH THE
MIDWEEK PERIOD AS HIGH PRESSURE SUSTAINS A WEAK GRADIENT.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....CB
UPDATE.......CB
SHORT TERM...BT
LONG TERM....MR
MARINE.......MR
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
120 PM EDT TUE MAY 5 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 503 AM EDT TUE MAY 5 2015
WV IMAGERY AND RUC ANALYSIS INDICATED CONFLUENT WRLY MID/UPPER LEVEL
FLOW INTO THE NRN GREAT LAKES BETWEEN A TROUGH OVER HUDSON BAY AND A
RIDGE FROM THE SE CONUS INTO THE CNTRL PLAINS. WITH A SFC RIDGE
EXTENDING FROM NW ONTARIO THROUGH THE NRN LAKES...LIGHT WINDS AND
CLEAR SKIES OVER UPPER MI HAS ALLOWED TEMPS TO DROP OFF INTO THE MID
AND UPPER 30S WITH SEVERAL INLAND COLD SPOTS IN THE UPPER 20S TO
AROUND 30. CLOUDS AND
TODAY...EXPECT THAT HIGH PRES WILL CONTINUE TO DOMINATE AS THE
CLOUDS AND PCPN ASSOCIATED WITH A FRONTAL BOUNDARY FROM SRN IA INTO
NRN IL REMAIN WELL TO THE SOUTH. MIXING TO 5K FT WITH 850 MB TEMPS
FCST IN THE 6C TO 8C RANGE WILL SUPPORT HIGHS IN THE UPPER 60S TO
AROUND 70...EXCEPT ALONG THE GREAT LAKES WHERE READING WILL REMAIN
IN THE UPPER 50S AND LOWER 60S. SIMILAR TO MONDAY...AFTERNOON
DEWPOINTS WILL DROP INTO THE LOWER 20S WITH RH VALUES FROM 15 TO 20
PCT. HOWEVER...WINDS WILL REMAIN LIGHT...AOB 10 MPH.
TONIGHT...AS THE HIGH SHIFTS OFF TO THE EAST AND AND 850 MB WARM
FRONT APPROACHES FROM THE SOUTH...EXPECT INCREASING CLOUDS OVERNIGHT.
THIS WILL KEEP TEMPS FROM FALLING OFF AS MUCH WITH MIN READINGS IN
THE UPPER 30S TO AROUND 40. WITH THE VERY DRY AIRMASS IN PLACE...THE
SLOWER END OF GUIDANCE WAS FAVORED WITH THE PCPN ADVANCING FROM THE
SOUTH. SO...NO PCPN MENTION WAS INCLUDED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 1248 PM EDT TUE MAY 5 2015
THE APEX OF THE 500MB RIDGE WILL RESIDE FROM N MANITOBA THROUGH
CENTRAL UPPER AND LOWER MI AT 00Z THURSDAY WITH RAIN APPROACHING
FROM THE W-SW. THIS RAIN IS ASSOCIATED WITH A WAVE IN THE 500MB SW
FLOW OVER THE N PLAINS.
SE FLOW IN THE EVENING AT THE SFC WILL TURN MORE OUT OF THE S
OVERNIGHT...USHERING IN WARMER/MORE MOIST AIR. THIS AND 850MB TEMPS
OF 11-12C SHOULD KEEP DOWNSLOPE AREAS WEDNESDAY NIGHT/THURSDAY
MORNING FROM FALLING BELOW THE MID 50S FAR W. HIGHS ON THURSDAY IN
THE LOW 80S OVER THE INTERIOR AND FAR W DOWNSLOPE AREAS LOOKS
REASONABLE. OTHER LOCATIONS OVER THE E AND ACROSS THE TIP OF THE
KEWEENAW PENINSULA WILL BE MAINLY IN THE 60S AND 70S. THE CONTINUED
DRY CONDITIONS AND WARMER AIR...ALONG WITH INCREASING WINDS. WILL
CONTINUE TO HIGHLIGHT THE BREEZY CONDITIONS AND MODERATE RH VALUES
IN THE FWF.
AFTERNOON CONVECTION IS STILL IN QUESTION FOR THURSDAY...WITH FCST
SOLUTIONS STILL GOING ON THE IDEA THAT PRECIP WILL EITHER END UP
JUST FAR W OF MAINLY OVER LAKE SUPERIOR AND TO OUR S. MUCH OF THAT
WILL DEPEND ON THE EVOLUTION OF CONVECTION TO OUR SW. THE BEST
INSTABILITY REMAINS WELL TO OUR SW...CLOSER TO THE NEARING COLD
FRONT STRETCHING FROM THE SFC LOW OVER NW ONTARIO AND THE NW HALF OF
MN. THERE IS STILL SOME TEMPORAL DISCREPANCIES BETWEEN THE FCST
SOLUTIONS AT THIS POINT. THE 05/00Z ECMWF IS APPROX 6HRS SLOWER NOW
THAN THE GFS. THIS IS A CHANGE FROM 24HRS AGO...WHEN THE ECMWF WAS
ON THE FAST SIDE. AT THIS POINT IT LOOKS LIKE A BLENDED SOLUTION IS
MOST REASONABLE...AS THE ECMWF IS BACKED UP BY THE SLOWER 05/00Z
CANADIAN AND WHILE THE OPERATIONAL GFS IS QUICKEST IT IS RUNNING IN
LINE WITH THE 05/12Z NAM.
LOOK FOR THE LOW OVER CENTRAL ONTARIO AROUND 06Z FRIDAY TO EJECT
NE...DRAGGING THE COLD FRONT OVER E MN/FAR W LAKE SUPERIOR ACROSS
UPPER MI DURING THE DAY FRIDAY. A SECONDARY LOW RIDING UP THE COLD
FRONT FROM THE S PLAINS FRIDAY AFTERNOON WILL ACT TO STALL THE FRONT
ACROSS LOWER MI /AND POSSIBLY EVEN FAR E UPPER MI/ FRIDAY NIGHT INTO
SATURDAY MORNING. STILL EXPECTING ANOTHER BREEZY DAY FRIDAY WITH
WINDS OUT OF A MORE SW DIRECTION. NAM SOUNDINGS INDICATE THE
POTENTIAL FOR OVER 30KT GUSTS. WHILE THE GFS AGREES...IT DOES HAVE A
STRONGER INVERSION SET UP E WITH LIMIT MIXING...AND OVERALL LIGHTER
WINDS OVER THE W.
OVER THE W TWO-THIRDS OF UPPER MI A RIDGE OF HIGH PRESSURE WILL BE
OVERHEAD SATURDAY MORNING...BUILDING IN FROM W CENTRAL CANADA. THE
RIDGE WILL CONTINUE TO STRENGTHEN OVER THE AREA THROUGH SATURDAY
NIGHT AS THE HIGH SHIFTS ACROSS MANITOBA AND ONTARIO.
THE NEXT SYSTEM OF INTEREST WILL BE IN THE FORM OF LOW PRESSURE
ACROSS THE CENTRAL PLAINS AT 12Z SUNDAY. WILL AGAIN FOLLOW A BLENDED
SOLUTION FOR THIS TIME PERIOD AS THERE COULD BE SIGNIFICANT
DIFFERENCES COMPARING THE ECMWF PLACEMENT OF THE LOW OVER S MN/SW WI
AT 12Z AND THE GFS WHICH HAS IT STILL OVER NE/KS. THE LOW WILL
LIKELY DRIFT ACROSS S WI /CLOSER TO THE ECMWF SOLUTION/ ON
MONDAY...AND ACROSS S LOWER MI MONDAY NIGHT BEFORE EXITING E. WITH
EITHER SOLUTION KEEPING THE LOW TO OUR S...WILL CONTINUE THE BEST
CHANCE OF ANY PRECIP OVER THE S HALF OF THE CWA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 120 PM EDT TUE MAY 5 2015
EXPECT VFR CONDITIONS AND LIGHT WINDS AT ALL 3 TAF SITES THIS FCST
PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 503 AM EDT TUE MAY 5 2015
AS A TROUGH MOVES FROM THE PLAINS TO THE UPPER MS VALLEY...SRLY
WINDS WILL INCREASE TO AROUND 25 KNOTS OVER THE EAST BY LATE THU INTO
THU NIGHT. OTHERWISE...WINDS ARE EXPECTED TO REMAIN AT OR BELOW 20
KNOTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1249 PM EDT TUE MAY 5 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 503 AM EDT TUE MAY 5 2015
WV IMAGERY AND RUC ANALYSIS INDICATED CONFLUENT WRLY MID/UPPER LEVEL
FLOW INTO THE NRN GREAT LAKES BETWEEN A TROUGH OVER HUDSON BAY AND A
RIDGE FROM THE SE CONUS INTO THE CNTRL PLAINS. WITH A SFC RIDGE
EXTENDING FROM NW ONTARIO THROUGH THE NRN LAKES...LIGHT WINDS AND
CLEAR SKIES OVER UPPER MI HAS ALLOWED TEMPS TO DROP OFF INTO THE MID
AND UPPER 30S WITH SEVERAL INLAND COLD SPOTS IN THE UPPER 20S TO
AROUND 30. CLOUDS AND
TODAY...EXPECT THAT HIGH PRES WILL CONTINUE TO DOMINATE AS THE
CLOUDS AND PCPN ASSOCIATED WITH A FRONTAL BOUNDARY FROM SRN IA INTO
NRN IL REMAIN WELL TO THE SOUTH. MIXING TO 5K FT WITH 850 MB TEMPS
FCST IN THE 6C TO 8C RANGE WILL SUPPORT HIGHS IN THE UPPER 60S TO
AROUND 70...EXCEPT ALONG THE GREAT LAKES WHERE READING WILL REMAIN
IN THE UPPER 50S AND LOWER 60S. SIMILAR TO MONDAY...AFTERNOON
DEWPOINTS WILL DROP INTO THE LOWER 20S WITH RH VALUES FROM 15 TO 20
PCT. HOWEVER...WINDS WILL REMAIN LIGHT...AOB 10 MPH.
TONIGHT...AS THE HIGH SHIFTS OFF TO THE EAST AND AND 850 MB WARM
FRONT APPROACHES FROM THE SOUTH...EXPECT INCREASING CLOUDS OVERNIGHT.
THIS WILL KEEP TEMPS FROM FALLING OFF AS MUCH WITH MIN READINGS IN
THE UPPER 30S TO AROUND 40. WITH THE VERY DRY AIRMASS IN PLACE...THE
SLOWER END OF GUIDANCE WAS FAVORED WITH THE PCPN ADVANCING FROM THE
SOUTH. SO...NO PCPN MENTION WAS INCLUDED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 1248 PM EDT TUE MAY 5 2015
THE APEX OF THE 500MB RIDGE WILL RESIDE FROM N MANITOBA THROUGH
CENTRAL UPPER AND LOWER MI AT 00Z THURSDAY WITH RAIN APPROACHING
FROM THE W-SW. THIS RAIN IS ASSOCIATED WITH A WAVE IN THE 500MB SW
FLOW OVER THE N PLAINS.
SE FLOW IN THE EVENING AT THE SFC WILL TURN MORE OUT OF THE S
OVERNIGHT...USHERING IN WARMER/MORE MOIST AIR. THIS AND 850MB TEMPS
OF 11-12C SHOULD KEEP DOWNSLOPE AREAS WEDNESDAY NIGHT/THURSDAY
MORNING FROM FALLING BELOW THE MID 50S FAR W. HIGHS ON THURSDAY IN
THE LOW 80S OVER THE INTERIOR AND FAR W DOWNSLOPE AREAS LOOKS
REASONABLE. OTHER LOCATIONS OVER THE E AND ACROSS THE TIP OF THE
KEWEENAW PENINSULA WILL BE MAINLY IN THE 60S AND 70S. THE CONTINUED
DRY CONDITIONS AND WARMER AIR...ALONG WITH INCREASING WINDS. WILL
CONTINUE TO HIGHLIGHT THE BREEZY CONDITIONS AND MODERATE RH VALUES
IN THE FWF.
AFTERNOON CONVECTION IS STILL IN QUESTION FOR THURSDAY...WITH FCST
SOLUTIONS STILL GOING ON THE IDEA THAT PRECIP WILL EITHER END UP
JUST FAR W OF MAINLY OVER LAKE SUPERIOR AND TO OUR S. MUCH OF THAT
WILL DEPEND ON THE EVOLUTION OF CONVECTION TO OUR SW. THE BEST
INSTABILITY REMAINS WELL TO OUR SW...CLOSER TO THE NEARING COLD
FRONT STRETCHING FROM THE SFC LOW OVER NW ONTARIO AND THE NW HALF OF
MN. THERE IS STILL SOME TEMPORAL DISCREPANCIES BETWEEN THE FCST
SOLUTIONS AT THIS POINT. THE 05/00Z ECMWF IS APPROX 6HRS SLOWER NOW
THAN THE GFS. THIS IS A CHANGE FROM 24HRS AGO...WHEN THE ECMWF WAS
ON THE FAST SIDE. AT THIS POINT IT LOOKS LIKE A BLENDED SOLUTION IS
MOST REASONABLE...AS THE ECMWF IS BACKED UP BY THE SLOWER 05/00Z
CANADIAN AND WHILE THE OPERATIONAL GFS IS QUICKEST IT IS RUNNING IN
LINE WITH THE 05/12Z NAM.
LOOK FOR THE LOW OVER CENTRAL ONTARIO AROUND 06Z FRIDAY TO EJECT
NE...DRAGGING THE COLD FRONT OVER E MN/FAR W LAKE SUPERIOR ACROSS
UPPER MI DURING THE DAY FRIDAY. A SECONDARY LOW RIDING UP THE COLD
FRONT FROM THE S PLAINS FRIDAY AFTERNOON WILL ACT TO STALL THE FRONT
ACROSS LOWER MI /AND POSSIBLY EVEN FAR E UPPER MI/ FRIDAY NIGHT INTO
SATURDAY MORNING. STILL EXPECTING ANOTHER BREEZY DAY FRIDAY WITH
WINDS OUT OF A MORE SW DIRECTION. NAM SOUNDINGS INDICATE THE
POTENTIAL FOR OVER 30KT GUSTS. WHILE THE GFS AGREES...IT DOES HAVE A
STRONGER INVERSION SET UP E WITH LIMIT MIXING...AND OVERALL LIGHTER
WINDS OVER THE W.
OVER THE W TWO-THIRDS OF UPPER MI A RIDGE OF HIGH PRESSURE WILL BE
OVERHEAD SATURDAY MORNING...BUILDING IN FROM W CENTRAL CANADA. THE
RIDGE WILL CONTINUE TO STRENGTHEN OVER THE AREA THROUGH SATURDAY
NIGHT AS THE HIGH SHIFTS ACROSS MANITOBA AND ONTARIO.
THE NEXT SYSTEM OF INTEREST WILL BE IN THE FORM OF LOW PRESSURE
ACROSS THE CENTRAL PLAINS AT 12Z SUNDAY. WILL AGAIN FOLLOW A BLENDED
SOLUTION FOR THIS TIME PERIOD AS THERE COULD BE SIGNIFICANT
DIFFERENCES COMPARING THE ECMWF PLACEMENT OF THE LOW OVER S MN/SW WI
AT 12Z AND THE GFS WHICH HAS IT STILL OVER NE/KS. THE LOW WILL
LIKELY DRIFT ACROSS S WI /CLOSER TO THE ECMWF SOLUTION/ ON
MONDAY...AND ACROSS S LOWER MI MONDAY NIGHT BEFORE EXITING E. WITH
EITHER SOLUTION KEEPING THE LOW TO OUR S...WILL CONTINUE THE BEST
CHANCE OF ANY PRECIP OVER THE S HALF OF THE CWA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 732 AM EDT TUE MAY 5 2015
WITH DRY HIGH PRESSURE DOMINATING...EXPECT VFR CONDITIONS AND LIGHT
WINDS AT ALL 3 TAF SITES THIS FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 503 AM EDT TUE MAY 5 2015
AS A TROUGH MOVES FROM THE PLAINS TO THE UPPER MS VALLEY...SRLY
WINDS WILL INCREASE TO AROUND 25 KNOTS OVER THE EAST BY LATE THU INTO
THU NIGHT. OTHERWISE...WINDS ARE EXPECTED TO REMAIN AT OR BELOW 20
KNOTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1034 AM EDT TUE MAY 5 2015
.UPDATE...
THE DETAILED FORECAST REASONING PROVIDED IN THE EARLY MORNING
DISCUSSION WAS WELL DONE AND REMAINS VALID.
A MATURE MCS AND COMPLEX OF SHORTWAVE ENERGY SUPPORTED BY RIGHT
ENTRANCE REGION DYNAMICS ALOFT IS CURRENTLY LIFTING INTO
SOUTHEASTERN MICHIGAN THIS MORNING. SURFACE PRECIPITATION REPORTS
SUPPORT LIGHT TO MODERATE RAIN OCCURRING WITHIN THE
FORWARD...WARM AIR ADVECTION QUADRANTS OF THE MCS. WITH THE RAIN
MOVING IN...SOUTHEASTERN MICHIGAN CAN EXPECT CATEGORICAL/PERIODS
OF RAIN THROUGHOUT THE AFTERNOON HOURS. FORECAST UNCERTAINTY FOR
THE SHORT TERM PERIOD CENTERS ON WHEN EXACTLY SYNOPTIC
SUPPORT/RAIN WILL END OVER THE AREA. LATEST NAM AND RAP ARE REALLY
PAINTING DIFFERENT PICTURES. NAM SUGGESTS SUBSIDENCE IN THE WAKE
OF THIS MCS...MAY BRING A QUIET PERIOD EARLY THIS EVENING...WHILE
THE RAP DRAGS OUT THE DURATION OF THIS CATEGORICAL RAIN INTO THE
EVENING. THERE REMAINS A WINDOW OF OPPORTUNITY FOR SOME THUNDER
CHANCES LATE THIS AFTERNOON...POST 20Z. THOSE CHANCES APPEAR TO
HINGE ON THE LIKELIHOOD OF THE NAM SOLUTION VERIFYING. NEGLIGIBLE
CONVECTIVE INSTABILITY YIELDS NO SUPPORT FOR SEVERE THUNDERSTORM
POTENTIAL.
&&
.AVIATION...ISSUED 707 AM EDT TUE MAY 5 2015
A NOTABLE DECREASE IN LIGHTNING WITHIN ONGOING ACTIVITY MOVING IN
FROM THE WEST FOR THE MORNING. A FEW STRAY LIGHTNING STRIKES WILL BE
POSSIBLE BUT MORE LIKELY AN MVFR RESTRICTION DUE TO A HEAVIER
DOWNPOUR OF RAIN. EXPECT MVFR RESTRICTION DUE TO LOW VISIBILITY IN
SHOWERS INITIALLY...ESPECIALLY PTK TO FNT WHERE THE MOST PERSISTENT
RAIN WILL SET UP...AND THEN MVFR DUE TO LOW CEILING LATER TODAY AND
THIS EVENING. IFR CEILING IS THEN LIKELY OVERNIGHT INTO WEDNESDAY
MORNING AS THE SURFACE FRONT DRIFTS NORTHWARD FROM INDIANA AND OHIO.
FOR DTW... SHOWERS WILL MOVE INTO THE TERMINAL AREA SHORTLY AFTER
ISSUANCE TIME AND THEN PERSIST THROUGH THE MORNING. THE HEAVIEST AND
MOST FREQUENT ACTIVITY WILL THEN SHIFT NORTH DURING THE AFTERNOON.
THERE IS A LATE AFTERNOON OR EARLY EVENING WINDOW FOR THUNDERSTORMS
BUT THIS WILL DEPEND ON THE EXTENT OF DEVELOPMENT ALONG THE SURFACE
FRONT DURING PEAK DAYTIME HEATING. OTHERWISE...CEILING WILL LOWER
STEADILY INTO MVFR THROUGH THE EVENING AND THEN IFR OVERNIGHT
THROUGH WEDNESDAY MORNING AS THE SURFACE FRONT DRIFTS CLOSER FROM
INDIANA AND OHIO.
//DTW THRESHOLD PROBABILITIES...
* HIGH FOR CEILING BELOW 5000 FT TODAY AND TONIGHT.
* LOW FOR THUNDERSTORMS TODAY AND TONIGHT.
&&
.PREV DISCUSSION...ISSUED 355 AM EDT TUE MAY 5 2015
SHORT TERM... TODAY AND TONIGHT
A WET 24 HOUR PERIOD IS SETTING UP OVER SOUTHERN LOWER MICHIGAN
TODAY THROUGH TONIGHT. THE TRI CITIES AND NORTHERN THUMB MAY ESCAPE
THE BULK OF THE RAINFALL TODAY BUT THE REST OF SE MICHIGAN STANDS TO
PICK UP A PROLONGED PERIOD OF SHOWERS AND THUNDERSTORMS. THE SURFACE
FRONT WILL REMAIN SOUTH OF THE OHIO BORDER THROUGH THE PERIOD SO
THUNDERSTORMS WILL BE THE ELEVATED VARIETY AND MAINLY CONTRIBUTE TO
LOCALLY HEAVY DOWNPOURS. RAINFALL TOTALS LOCALLY AROUND 1 INCH WILL
BE POSSIBLE BY SUNRISE WEDNESDAY.
WIDESPREAD SHOWERS AND THUNDERSTORMS ARE ALREADY UNDERWAY OVER THE
MIDWEST AND WILL SPREAD TO THE NORTH AND EAST DURING THE REST OF THE
MORNING. THIS AREA OF CONVECTION ORIGINATED ALONG THE FRONT OVER THE
CENTRAL PLAINS DURING PEAK HEATING YESTERDAY AND HAS SINCE GROWN
LARGE ENOUGH AND PERSISTENT ENOUGH TO SUPPORT MCV DEVELOPMENT ALOFT
AND AN AREA OF SURFACE PRESSURE FALLS OVER IOWA AND MISSOURI. THE
WAVE IS JUST STRONG ENOUGH TO SUPPORT A WEAK LOW LEVEL JET FUELING
ACTIVITY OVER NORTHERN ILLINOIS WHICH WILL CONTINUE TO DEVELOP INTO
SOUTHERN LOWER MICHIGAN AS THE LOW TO MID LEVELS OF THE FRONT
STRENGTHEN WITH TIME. CONVECTIVE DEBRIS IN SATELLITE IMAGERY SHOWS
THE ENTRANCE REGION OF A 120 KNOT UPPER JET ANALYZED IN MODEL DATA
AT 250 MB. THIS FEATURE IS POSITIONED FAVORABLY OVER THE GREAT LAKES
TO GENERATE STRONG FRONTOGENESIS THROUGH TODAY WHILE THE LARGE SCALE
FRONTAL POSITION REMAINS STATIONARY AND THEN DRIFTS SLOWLY NORTHWARD
TONIGHT. CROSS SECTIONS OF MODEL DATA FROM THE POSITION OF THE
SURFACE FRONT EXTENDING NORTHWARD TO THE UPPER JET AXIS SHOW THE
STEEPEST PORTION OF THE AGEOSTROPHIC CIRCULATION SETTING UP THROUGH
CENTRAL SECTIONS OF OUR AREA BY AFTERNOON THROUGH THIS EVENING. DEEP
CONVECTIVE INSTABILITY ABOVE THE FRONTAL SURFACE COMBINED WITH
PRECIPITABLE WATER RISING TO ABOUT 1.25 INCHES WILL ENSURE
WIDESPREAD COVERAGE OF SHOWERS WITH EMBEDDED THUNDERSTORMS. LOCALLY
HEAVY RAINFALL WILL ALSO BE POSSIBLE DUE TO THE PERSISTENCE OF THIS
TEXTBOOK UPPER JET ENHANCED FRONTAL CIRCULATION AND THE CONVECTIVE
NATURE OF THE PRECIPITATION PATTERN. SO THEN WHAT COULD GO WRONG IN
THIS FORECAST? THE POTENTIAL FOR SURFACE BASED CONVECTION OVER
INDIANA AND OHIO...COMBINED WITH THE TENDENCY FOR ELEVATED
INSTABILITY TO BECOME LESS EFFECTIVE DURING THE DAY...COULD LEAD TO
A WEAKENING TREND IN THE PATTERN OVER SE MICHIGAN DURING THE
AFTERNOON INTO THIS EVENING. SHOULD THIS OCCUR...IT WOULD DO MORE TO
REDUCE THE POTENTIAL FOR HEAVY RAINFALL IN OUR AREA AND POSSIBLY
ALTER THE LOCATION OF THE MOST PERSISTENT SHOWERS AND OVERALL QPF...
BUT MOST AREAS WILL SEE A LENGTHY PERIOD OF RAIN AS THE MORNING RAMP
UP WOULD CARRY OVER INTO THE AFTERNOON JUST BASED ON INERTIA.
PROGRESSION OF THE UPPER LEVEL RIDGE AND THE ENTRANCE REGION OF THE
UPPER JET WILL NUDGE THE MID LEVEL FRONTAL ZONE TO THE NORTH AND
EAST OVERNIGHT. THIS WILL BRING THE TRI CITIES AND NORTHERN THUMB
MORE INTO THE PATTERN OF REMAINING SHOWERS AND WILL BE THE FAVORED
LOCATION FOR ANY NOCTURNAL REDEVELOPMENT. THE AXIS OF LIKELY POPS
OVER SE MICHIGAN IS PLACED ALONG THE 850 MB THETA-E GRADIENT WHICH
IS WELL AGREED UPON BY THE 00Z MODEL CYCLE AND IS THE MOST FAVORED
LOCATION FOR RENEWED DEVELOPMENT OF NOCTURNAL ELEVATED INSTABILITY
AND SUPPORT FOR SHOWERS THROUGH SUNRISE WEDNESDAY.
LONG TERM...WEDNESDAY THROUGH MONDAY
SE MICHIGAN WILL RESIDE ALONG THE IMMEDIATE DOWNSTREAM SIDE OF AN
ELONGATING UPPER RIDGE ON WEDNESDAY. THE RESULTING WEAKLY SHEARED
WEST-NORTHWEST FLOW WILL SUSTAIN A PERTURBED 850-925 MB FRONTAL ZONE
ACROSS THE REGION. MODELS TRENDING SLIGHTLY STRONGER WITH THE
ASCENT/CONVERGENCE THROUGH THIS LAYER...SUGGESTING THE EXISTING
FRONTAL SLOPE WILL POTENTIALLY BE MORE ACTIVE. THIS WILL SUPPORT
THE INCLUSION OF A LOWER END POP. GREATER POTENTIAL FOR SHOWER
PRODUCTION DURING THE MORNING PERIOD...BEFORE BOTH THE MOISTURE
QUALITY AND AVAILABLE FORCING DIMINISHES AS THE INBOUND UPPER RIDGE
MAKES BETTER INROADS. SUBSTANTIAL CLOUD COVER WITHIN PERSISTENT LOW
LEVEL EASTERLY FLOW WILL CAP THE DIURNAL TEMPERATURE RESPONSE TO
SOME DEGREE...REGARDLESS OF SHOWER COVERAGE. ABSENT OF A LARGER AND
PERSISTENT COVERAGE OF SHOWERS TO DISRUPT THE HEATING CYCLE...
EXISTING THERMAL PROFILE WILL SUPPORT HIGHS GENERALLY WITHIN THE MID
AND UPPER 60S RANGE.
UPPER RIDGE STEADILY BUILDS INTO LOWER MICHIGAN WEDNESDAY NIGHT...
580 DM AT 500 MB MARKING THE RIDGE AXIS CENTERING OVERHEAD BY EARLY
THURSDAY MORNING. THIS PROGRESSION WILL SEND SE MICHIGAN INTO THE
WARM SECTOR BY THURSDAY...SOLID DEPTH TO THE EMERGING SOUTHWEST FLOW
CONTINUING TO POINT TOWARD HIGHS MAKING A RUN INTO THE LOWER 80S.
DRY/STABLE PROFILE STILL INFLUENCED BY EXITING UPPER RIDGING WILL
RESULT IN LITTLE MORE THAN A STANDARD DIURNAL CU FIELD.
CLOSED LOW CURRENTLY PARKED OVER THE DESERT SOUTHWEST WILL LIFT
NORTHEAST THROUGH THE LATTER HALF OF THE WEEK...EVENTUALLY SHEARING
OVER THE TOP OF THE UPPER RIDGE STAGNATING ALONG THE EAST COAST.
THIS LOWERING HEIGHT FIELD WILL BEGIN TO EASE AN ATTENDANT FRONTAL
BOUNDARY EASTWARD WITHIN THE FRIDAY AND SATURDAY WINDOW. GENERAL
TIMING ACROSS THE MODEL SPECTRUM SUGGESTS FRIDAY WILL REMAIN
CHARACTERED BY THE PRE-FRONTAL WARM SECTOR...WITH ANY POSSIBLE LATE
DAY/EVENING CONVECTIVE CHANCES ARRIVING TOO LATE TO DISRUPT ANOTHER
DAY WITH HIGHS IN THE 80S. POTENTIAL IS THERE FOR AN ACTIVE PERIOD
HEADING INTO THE UPCOMING WEEKEND...FRONTAL BOUNDARY EVENTUALLY
ALIGNING OVER OR NEAR THE REGION FOR AN EXTENDED TIME AS THE AXIS
BECOMES PARALLEL TO THE MEAN FLOW. THIS PATTERN WOULD SHAVE A FEW
DEGREE OFF PROSPECTIVE HIGHS THIS WEEKEND RELATIVE TO THE
THU/FRI WARMTH...STILL NEAR TO ABOVE NORMAL THROUGH THIS TIME.
MARINE...
SHOWERY CONDITIONS WITH THE CHANCE OF THUNDERSTORMS WILL EXIST UNDER
PERSIST EAST TO NORTHEAST FLOW OVER THE SOUTHERN LAKE HURON BASIN
AND POINTS SOUTHWARD THROUGH TONIGHT. FAVORABLE MARINE CONDITIONS
ACROSS NORTHERN LAKE HURON DURING THIS TIME AS HIGH PRESSURE BUILDS
INTO THE REGION. MODEST WAVE AND WIND CONDITIONS THROUGH THE
MIDWEEK PERIOD AS HIGH PRESSURE SUSTAINS A WEAK GRADIENT.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
UPDATE.......CB
AVIATION.....BT
SHORT TERM...BT
LONG TERM....MR
MARINE.......MR
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
734 AM EDT TUE MAY 5 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 503 AM EDT TUE MAY 5 2015
WV IMAGERY AND RUC ANALYSIS INDICATED CONFLUENT WRLY MID/UPPER LEVEL
FLOW INTO THE NRN GREAT LAKES BETWEEN A TROUGH OVER HUDSON BAY AND A
RIDGE FROM THE SE CONUS INTO THE CNTRL PLAINS. WITH A SFC RIDGE
EXTENDING FROM NW ONTARIO THROUGH THE NRN LAKES...LIGHT WINDS AND
CLEAR SKIES OVER UPPER MI HAS ALLOWED TEMPS TO DROP OFF INTO THE MID
AND UPPER 30S WITH SEVERAL INLAND COLD SPOTS IN THE UPPER 20S TO
AROUND 30. CLOUDS AND
TODAY...EXPECT THAT HIGH PRES WILL CONTINUE TO DOMINATE AS THE
CLOUDS AND PCPN ASSOCIATED WITH A FRONTAL BOUNDARY FROM SRN IA INTO
NRN IL REMAIN WELL TO THE SOUTH. MIXING TO 5K FT WITH 850 MB TEMPS
FCST IN THE 6C TO 8C RANGE WILL SUPPORT HIGHS IN THE UPPER 60S TO
AROUND 70...EXCEPT ALONG THE GREAT LAKES WHERE READING WILL REMAIN
IN THE UPPER 50S AND LOWER 60S. SIMILAR TO MONDAY...AFTERNOON
DEWPOINTS WILL DROP INTO THE LOWER 20S WITH RH VALUES FROM 15 TO 20
PCT. HOWEVER...WINDS WILL REMAIN LIGHT...AOB 10 MPH.
TONIGHT...AS THE HIGH SHIFTS OFF TO THE EAST AND AND 850 MB WARM
FRONT APPROACHES FROM THE SOUTH...EXPECT INCREASING CLOUDS OVERNIGHT.
THIS WILL KEEP TEMPS FROM FALLING OFF AS MUCH WITH MIN READINGS IN
THE UPPER 30S TO AROUND 40. WITH THE VERY DRY AIRMASS IN PLACE...THE
SLOWER END OF GUIDANCE WAS FAVORED WITH THE PCPN ADVANCING FROM THE
SOUTH. SO...NO PCPN MENTION WAS INCLUDED.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 438 AM EDT TUE MAY 5 2015
ABOVE AVERAGE TEMPS WILL CONTINUE THROUGH THE WEEK AMIDST SMALL
CHANCES OF PRECIP WEDNESDAY...AND A CHANCE OF SHOWERS AND STORMS
LATE THURSDAY INTO FRIDAY. MUCH COOLER WEATHER WILL THEN RETURN FOR
THE WEEKEND.
WEDNESDAY AND WEDNESDAY NIGHT...A STOUT MID-LEVEL RIDGE WILL BE
ENTERING THE WESTERN CWA AT 12Z WED AS AN ASSOCIATED SFC HIGH OVER
GEORGIAN BAY SHIFTS SOUTHEASTWARD. MEANWHILE...A SHORTWAVE TROUGH
DRIFTING NE FROM THE SOUTHERN ROCKIES WILL BEGIN TO CONSOLIDATE A
BROAD SFC TROUGH ALONG THE ENTIRE U.S. ROCKIES. MODELS CONTINUE
THEIR TWO-DAY TREND IN LOWERING QPF ALONG AN 850 HPA WARM FRONT
ACROSS THE SW CWA WED MORNING. IN FACT...MOST OF THE HIGHER-RES
GUIDANCE SUITE SHOWS VERY LITTLE PRECIP DURING THE DAY WEDNESDAY.
THE STEEP MID-LEVEL RIDGE IS PROVING TO BE TOO MUCH TO MAINTAIN MOST
OF THE INCOMING RAIN SHOWERS FROM WI. ADDITIONALLY...THE BULK OF THE
BETTER LOW-LEVEL MOISTURE WILL REMAIN ACROSS MN. HAVE THUS OPTED TO
CUT NEARLY ALL CHANCES OF PRECIP EXCEPT FOR A SLIGHT CHANCE FOR
SHOWERS ALONG THE WI BORDER IN THE MORNING.
THURSDAY THROUGH FRIDAY...AFTER THE H8 WARM FRONT CROSSES THE
CWA...THERE IS LITTLE SUPPORT FOR PRECIP UNTIL AT LEAST THURSDAY
AFTERNOON. ADDITIONALLY...CAPPING AROUND 750 HPA SHOULD KEEP PRECIP
CHANCES LIMITED THROUGH THURSDAY MORNING. THE SFC COLD FRONT UNDER
INCREASING MOISTURE FROM AN H8 50KT JET AND A DEVELOPING LEFT-EXIT
OF A WEAK UPPER JET STREAK SHOULD BE ENOUGH TO RESULT IN SCATTERED
SHOWERS AND THUNDERSTORMS LATE THU AFTERNOON THROUGH MUCH OF THU
NIGHT. HOWEVER...KEPT POPS AT JUST A CHANCE OF SHOWERS AND
THUNDERSTORMS AS THE BEST MID-LEVEL FORCING PEELS OFF TO THE NORTH.
TEMPS COULD GET QUITE WARM THU IF ENOUGH AFTERNOON CLEARING OCCURS.
GIVEN THE CAP...THINK THERE WILL BE ENOUGH INSOLATION TO BOOST TEMPS
INTO THE LOW 80S ACROSS THE WEST UNDER H8 TEMPS UP TO 14C. IN
ADDITION TO THE WARMER WX...MIXING INTO 35 TO 45KT WINDS SHOULD
RESULT IN QUITE A GUSTY DAY...ESPECIALLY WEST. EVEN THOUGH MUCH OF
WEST DID NOT BENEFIT FROM SATURDAYS PRECIP...FIRE WX CONCERNS SHOULD
BE PARTIALLY MITIGATED BY INCREASING LOW-LEVEL MOISTURE...RESULTING
IN MIN RH VALUES ONLY INTO THE UPPER 30S. HOWEVER...FIRE INDICES
ARE BEGINNING TO INDICATE INCREASING FIRE POTENTIAL ACROSS THE
WEST...SO THURSDAY WILL NEED TO BE MONITORED IF LOW-LEVEL MOISTURE
IS SLOW TO ARRIVE.
FRIDAY...THE COLD FRONT LOOKS TO CLEAR THE CWA BY FRIDAY
AFTERNOON...ENDING PRECIP CHANCES AND USHERING IN COOLER AIR. TEMPS
WILL DROP ALONG PORTIONS OF LAKE SUPERIOR DURING THE AFTERNOON HOURS
AS WINDS BECOME NW.
SATURDAY...THE ECMWF AND CANADIAN GEM STRUGGLE TO PUSH THE COLD
FRONT FAR AWAY FROM THE CWA...LEAVING LINGERING CHANCES OF SHOWERS
ACROSS THE SE HALF. THE GFS KEEPS THE AREA DRY...AND GIVEN ITS
BETTER RUN TO RUN CONSISTENCY WITH THIS SYSTEM...HAVE OPTED TO KEEP
NEARLY ALL POPS OUT OF THE CWA. HOWEVER...SOME SPRINKLES/DRIZZLE
CANNOT BE RULED OUT ALONG LAKE SUPERIOR...WHERE N WINDS AND
LINGERING LOW-LEVEL MOISTURE SHOULD RESULT IN DECENT LOW-LEVEL
CLOUDS. ADDITIONALLY...TEMPS WILL LIKELY STRUGGLE TO REACH 50F NEAR
THE SHORE.
SUNDAY AND MONDAY...MODEL DIFFERENCE QUICKLY DEVELOP WITH THE
HANDLING OF A DEEP TROUGH EXITING THE WESTERN CONUS. FOLLOWING THE
GFS SOLUTION...A SFC LOW IN THE LEE OF THE ROCKIES WILL TRACK ENE
ALONG THE STALLED W TO E SFC BOUNDARY BIFURCATING THE CENTRAL CONUS.
THE ECMWF AND CANADIAN GEM TRACK THE LOW FARTHER NORTH. ABUNDANT
CONVECTION ACROSS THE PLAINS ONLY LEADS TO MORE UNCERTAINTY WITH THE
SYNOPTIC EVOLUTION OF THIS SYSTEM...SO HAD TO RESORT TO USING
CONSENSUS CHANCE POPS SUNDAY AFTERNOON THROUGH MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 732 AM EDT TUE MAY 5 2015
WITH DRY HIGH PRESSURE DOMINATING...EXPECT VFR CONDITIONS AND LIGHT
WINDS AT ALL 3 TAF SITES THIS FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 503 AM EDT TUE MAY 5 2015
AS A TROUGH MOVES FROM THE PLAINS TO THE UPPER MS VALLEY...SRLY
WINDS WILL INCREASE TO AROUND 25 KNOTS OVER THE EAST BY LATE THU INTO
THU NIGHT. OTHERWISE...WINDS ARE EXPECTED TO REMAIN AT OR BELOW 20
KNOTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KLUBER
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
504 AM EDT TUE MAY 5 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 503 AM EDT TUE MAY 5 2015
WV IMAGERY AND RUC ANALYSIS INDICATED CONFLUENT WRLY MID/UPPER LEVEL
FLOW INTO THE NRN GREAT LAKES BETWEEN A TROUGH OVER HUDSON BAY AND A
RIDGE FROM THE SE CONUS INTO THE CNTRL PLAINS. WITH A SFC RIDGE
EXTENDING FROM NW ONTARIO THROUGH THE NRN LAKES...LIGHT WINDS AND
CLEAR SKIES OVER UPPER MI HAS ALLOWED TEMPS TO DROP OFF INTO THE MID
AND UPPER 30S WITH SEVERAL INLAND COLD SPOTS IN THE UPPER 20S TO
AROUND 30. CLOUDS AND
TODAY...EXPECT THAT HIGH PRES WILL CONTINUE TO DOMINATE AS THE
CLOUDS AND PCPN ASSOCIATED WITH A FRONTAL BOUNDARY FROM SRN IA INTO
NRN IL REMAIN WELL TO THE SOUTH. MIXING TO 5K FT WITH 850 MB TEMPS
FCST IN THE 6C TO 8C RANGE WILL SUPPORT HIGHS IN THE UPPER 60S TO
AROUND 70...EXCEPT ALONG THE GREAT LAKES WHERE READING WILL REMAIN
IN THE UPPER 50S AND LOWER 60S. SIMILAR TO MONDAY...AFTERNOON
DEWPOINTS WILL DROP INTO THE LOWER 20S WITH RH VALUES FROM 15 TO 20
PCT. HOWEVER...WINDS WILL REMAIN LIGHT...AOB 10 MPH.
TONIGHT...AS THE HIGH SHIFTS OFF TO THE EAST AND AND 850 MB WARM
FRONT APPROACHES FROM THE SOUTH...EXPECT INCREASING CLOUDS OVERNIGHT.
THIS WILL KEEP TEMPS FROM FALLING OFF AS MUCH WITH MIN READINGS IN
THE UPPER 30S TO AROUND 40. WITH THE VERY DRY AIRMASS IN PLACE...THE
SLOWER END OF GUIDANCE WAS FAVORED WITH THE PCPN ADVANCING FROM THE
SOUTH. SO...NO PCPN MENTION WAS INCLUDED.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 438 AM EDT TUE MAY 5 2015
ABOVE AVERAGE TEMPS WILL CONTINUE THROUGH THE WEEK AMIDST SMALL
CHANCES OF PRECIP WEDNESDAY...AND A CHANCE OF SHOWERS AND STORMS
LATE THURSDAY INTO FRIDAY. MUCH COOLER WEATHER WILL THEN RETURN FOR
THE WEEKEND.
WEDNESDAY AND WEDNESDAY NIGHT...A STOUT MID-LEVEL RIDGE WILL BE
ENTERING THE WESTERN CWA AT 12Z WED AS AN ASSOCIATED SFC HIGH OVER
GEORGIAN BAY SHIFTS SOUTHEASTWARD. MEANWHILE...A SHORTWAVE TROUGH
DRIFTING NE FROM THE SOUTHERN ROCKIES WILL BEGIN TO CONSOLIDATE A
BROAD SFC TROUGH ALONG THE ENTIRE U.S. ROCKIES. MODELS CONTINUE
THEIR TWO-DAY TREND IN LOWERING QPF ALONG AN 850 HPA WARM FRONT
ACROSS THE SW CWA WED MORNING. IN FACT...MOST OF THE HIGHER-RES
GUIDANCE SUITE SHOWS VERY LITTLE PRECIP DURING THE DAY WEDNESDAY.
THE STEEP MID-LEVEL RIDGE IS PROVING TO BE TOO MUCH TO MAINTAIN MOST
OF THE INCOMING RAIN SHOWERS FROM WI. ADDITIONALLY...THE BULK OF THE
BETTER LOW-LEVEL MOISTURE WILL REMAIN ACROSS MN. HAVE THUS OPTED TO
CUT NEARLY ALL CHANCES OF PRECIP EXCEPT FOR A SLIGHT CHANCE FOR
SHOWERS ALONG THE WI BORDER IN THE MORNING.
THURSDAY THROUGH FRIDAY...AFTER THE H8 WARM FRONT CROSSES THE
CWA...THERE IS LITTLE SUPPORT FOR PRECIP UNTIL AT LEAST THURSDAY
AFTERNOON. ADDITIONALLY...CAPPING AROUND 750 HPA SHOULD KEEP PRECIP
CHANCES LIMITED THROUGH THURSDAY MORNING. THE SFC COLD FRONT UNDER
INCREASING MOISTURE FROM AN H8 50KT JET AND A DEVELOPING LEFT-EXIT
OF A WEAK UPPER JET STREAK SHOULD BE ENOUGH TO RESULT IN SCATTERED
SHOWERS AND THUNDERSTORMS LATE THU AFTERNOON THROUGH MUCH OF THU
NIGHT. HOWEVER...KEPT POPS AT JUST A CHANCE OF SHOWERS AND
THUNDERSTORMS AS THE BEST MID-LEVEL FORCING PEELS OFF TO THE NORTH.
TEMPS COULD GET QUITE WARM THU IF ENOUGH AFTERNOON CLEARING OCCURS.
GIVEN THE CAP...THINK THERE WILL BE ENOUGH INSOLATION TO BOOST TEMPS
INTO THE LOW 80S ACROSS THE WEST UNDER H8 TEMPS UP TO 14C. IN
ADDITION TO THE WARMER WX...MIXING INTO 35 TO 45KT WINDS SHOULD
RESULT IN QUITE A GUSTY DAY...ESPECIALLY WEST. EVEN THOUGH MUCH OF
WEST DID NOT BENEFIT FROM SATURDAYS PRECIP...FIRE WX CONCERNS SHOULD
BE PARTIALLY MITIGATED BY INCREASING LOW-LEVEL MOISTURE...RESULTING
IN MIN RH VALUES ONLY INTO THE UPPER 30S. HOWEVER...FIRE INDICES
ARE BEGINNING TO INDICATE INCREASING FIRE POTENTIAL ACROSS THE
WEST...SO THURSDAY WILL NEED TO BE MONITORED IF LOW-LEVEL MOISTURE
IS SLOW TO ARRIVE.
FRIDAY...THE COLD FRONT LOOKS TO CLEAR THE CWA BY FRIDAY
AFTERNOON...ENDING PRECIP CHANCES AND USHERING IN COOLER AIR. TEMPS
WILL DROP ALONG PORTIONS OF LAKE SUPERIOR DURING THE AFTERNOON HOURS
AS WINDS BECOME NW.
SATURDAY...THE ECMWF AND CANADIAN GEM STRUGGLE TO PUSH THE COLD
FRONT FAR AWAY FROM THE CWA...LEAVING LINGERING CHANCES OF SHOWERS
ACROSS THE SE HALF. THE GFS KEEPS THE AREA DRY...AND GIVEN ITS
BETTER RUN TO RUN CONSISTENCY WITH THIS SYSTEM...HAVE OPTED TO KEEP
NEARLY ALL POPS OUT OF THE CWA. HOWEVER...SOME SPRINKLES/DRIZZLE
CANNOT BE RULED OUT ALONG LAKE SUPERIOR...WHERE N WINDS AND
LINGERING LOW-LEVEL MOISTURE SHOULD RESULT IN DECENT LOW-LEVEL
CLOUDS. ADDITIONALLY...TEMPS WILL LIKELY STRUGGLE TO REACH 50F NEAR
THE SHORE.
SUNDAY AND MONDAY...MODEL DIFFERENCE QUICKLY DEVELOP WITH THE
HANDLING OF A DEEP TROUGH EXITING THE WESTERN CONUS. FOLLOWING THE
GFS SOLUTION...A SFC LOW IN THE LEE OF THE ROCKIES WILL TRACK ENE
ALONG THE STALLED W TO E SFC BOUNDARY BIFURCATING THE CENTRAL CONUS.
THE ECMWF AND CANADIAN GEM TRACK THE LOW FARTHER NORTH. ABUNDANT
CONVECTION ACROSS THE PLAINS ONLY LEADS TO MORE UNCERTAINTY WITH THE
SYNOPTIC EVOLUTION OF THIS SYSTEM...SO HAD TO RESORT TO USING
CONSENSUS CHANCE POPS SUNDAY AFTERNOON THROUGH MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 135 AM EDT TUE MAY 5 2015
WITH DRY HI PRES DOMINATING...EXPECT VFR CONDITIONS AND LIGHT WINDS
AT ALL 3 TAF SITES THIS FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 503 AM EDT TUE MAY 5 2015
AS A TROUGH MOVES FROM THE PLAINS TO THE UPPER MS VALLEY...SRLY
WINDS WILL INCREASE TO AROUND 25 KNOTS OVER THE EAST BY LATE THU INTO
THU NIGHT. OTHERWISE...WINDS ARE EXPECTED TO REMAIN AT OR BELOW 20
KNOTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KLUBER
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
411 PM CDT Tue May 5 2015
.DISCUSSION...
Issued at 409 PM CDT TUE MAY 5 2015
Active pattern will continue through the rest of the week, and into
the weekend. Perhaps the quietest of the next several days will be
this afternoon. Warm and muggy conditions persist across the area
today, with temperatures in the middle 70s to lower 80s, with
dewpoints in the upper 50s to lower 60s. RAP soundings indicate that
the atmosphere is uncapped, which has allowed for the CU field to
form across the area. However the lack of any appreciable forcing
has prevented much in the way of thunderstorm development. That
being said, with the uncapped environment there is enough weak
forcing to get a few storms to form across central Missouri. These
storms will generally be pretty scattered in nature across the area,
but coverage will not be very great. Any shower will likely be
rather brief in nature. No strong or severe weather is anticipated
with any of these storms outside of a wind gust or two near the
storm. These diurnally driven showers will likely fall apart and
diminish around sunset.
Over the next several days several shortwave troughs will be rolling
through the area, bringing several chances of rain. The first
appreciable chance for rain will be during the morning to early
afternoon hours on Wednesday as a vorticity lobe will swing through
the area, bringing some scattered convection. While there will be
some instability in the area, on the order of 500 to 1000 J/kg the
amount of instability will be somewhat meager. Deep layer shear will
also be on the low side, with 20 to 30 kts of 0-6 km shear. So given
those particular CAPE/shear parameters it doesn`t look like severe
weather will be the main story for Wednesday, but some of those
morning and afternoon storms could be strong, to perhaps isolated
severe. With the instability axis generally lined up to the west,
the farther east any storms form will have a lessor chance to be
severe.
For Thursday another area of low pressure will eject through the
area, and perhaps be accompanied by convection rolling eastward off
the High Plains. This should kick off another round of convection
across the area. Thursday will likely bring quite a bit more
instability with ML CAPE values approaching 1000 to 2000 J/kg, but
shear will still be on the low end, with 0-6 km layer shear in the
20 to 30 kt range. Even though the CAPE/shear values are not
incredibly high they will be ample to possibly produced some
organized rotating cells, and perhaps an isolated supercell or two
across the area. Once again, the main threats will be hail and wind
for
Friday brings a slightly different story, as a surface boundary will
sag southward, and basically bisect the forecast area E-W. Friday
looks to be a little more capped than the previous couple of days,
and that convective inhibition is a bit more influenced by some
moderate height rises across the Plains for that time period. With
good turning in the atmosphere, characterized by veering-with-height
wind profile deep shear will be a bit higher, and instability will
be in the 1000 to 2000 J/kg range any storm that is able to go up on
Friday has a chance to be severe. If a storm does latch itself to
the boundary, which will be somewhere near I-70 it could get a
little extra low level turning, which would make any storm in that
area even stronger. Synoptically speaking Friday doesn`t seem to
bring much in the way of severe weather potential, but the mesoscale
forecast closer to the event might reveal some potential for some
isolated to scattered severe storms.
By Saturday, the chances for severe weather start to synoptically
increase. A very large trough, off to the west, will eventually take
on a negative tilt and move through the Central Plains this weekend.
Saturday still looks to be a little too far west to bring much in
the way of widespread severe weather to the area. But during the
overnight hours on Saturday night into Sunday morning the convection
that occurs over the western and central plains will likely roll
through the area. Convection during this overnight period would
likely not be as organized, but it could roll through as an
organized MCS, bringing a low end hail threat, but a larger wind
threat Saturday night into Sunday morning.
While this time period is still quite a way out, and much will
depend on how things pan out closer to the event, Sunday is looking
to be the day to watch as far as widespread severe weather across
eastern Kansas and western Missouri is concerned. Recent runs of the
GFS and ECMWF indicate a very potent mid level trough moving through
the area Saturday night and Sunday. At the surface there will likely
be a dry line somewhere between KDDC and KEMP. Where exactly the dry
line sets up will dictate whether heightened concern for significant
severe weather is warranted on Sunday. Should the dry line set up
farther west, as is indicated by the GFS, then the area might be
spared the brunt of the severe weather. But if it sets up near KEMP
or even a little farther east, then this area could see a rather
significant severe weather day on Sunday. But again, despite the
synoptic signal, and with the timing so far out, and with mesoscale
features playing a big roll in how convection plays out it`s much
too early to get super concerned about severe weather this weekend.
Also, despite the uncertainty regarding the timing, location, and
severity of the thunderstorm activity through the rest of the week
and into the weekend, there is also a very strong signal to support a
prolonged period of multiple rounds of heavy rain. Some areas could
see higher amounts, and some locations could see lower amounts, but
generally speaking there appears to be a good signal for several
inches of rain (perhaps up to 5 inches in some areas) through the
next 5 to 7 days.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon)
Issued at 1228 PM CDT TUE MAY 5 2015
Made some wholesale changes to this forecast. Most notably added a
VCTS group for this afternoon. Cumulus field on satellite, as well as
HRRR model guidance suggests a few scattered cells will be possible
across the area this afternoon. Tough call whether or not the
terminals will be directly affected, but there could be some
vicinity issues. Also, overnight added some wind gusts, per model guidance.
RAP sounding for the overnight period is a bit enigmatic with respect
to gusts reaching to surface due to diurnal decoupling, but would
suggest that if gusts don`t occur that a LLWS concern will develop
overnight, with winds around 40 kts about 800 feet off the surface.
Also added -SHRA group with VCTS for 15z Wed for rain showers
encroaching from the west.
J. Leighton
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...Leighton
AVIATION...Leighton
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
954 AM MDT TUE MAY 5 2015
.UPDATE...
MINOR ADJUSTMENTS TO THE GOING FORECAST TODAY. AREA WILL BE UNDER
A SOUTHERLY FLOW REGIME TODAY AHEAD OF TONIGHTS COLD FRONT. A
COUPLE OF DISTURBANCES CROSSING SOUTH TO NORTH OVER WESTERN ZONES
THIS AFTERNOON WILL TRIGGER ISOLATED TO SCATTERED THUNDERSTORMS.
SHEAR PROFILES AND INSTABILITY LOOK WEAK SO NOT EXPECTING ANY
SEVERE STORMS BUT COULD SEE AN ISOLATED STRONG WIND GUST WITH THIS
ACTIVITY. LOOKS LIKE THIS MORNING WILL BE MAINLY DRY SO DROPPED
MOST POPS BEFORE NOON. ALSO REMOVED MENTION OF AFTERNOON POPS FOR
SOUTHEAST MONTANA AS IT LOOKS CONVECTION WILL HOLD OFF UNTIL LATER
IN THE EVENING THERE. LOWERED RH/TD VALUES A BIT AS WELL AHEAD OF
THE FRONT. REST OF THE FORECAST IN PRETTY GOOD SHAPE. CHAMBERS
&&
.SHORT TERM...VALID FOR TDY AND WED...
UNSETTLED WEATHER BEGINS TODAY AND WILL CONTINUE RIGHT THROUGH
THE REMAINDER OF THE WEEK. AN UPPER LOW AND TROUGH WILL MOVE ONTO
THE PACIFIC NORTHWEST COAST TODAY AND REMAIN STATIONARY OR SLOWLY
SHIFT SOUTHEAST TOWARD THE GREAT BASIN AREA DURING THE DAY
WEDNESDAY. THIS WILL ALLOW A SOUTHWEST FLOW ALOFT TO BEGIN TO
DEVELOP OVER OUR AREA TODAY AND ESPECIALLY BE IN PLACE FOR
WEDNESDAY. SEVERAL SURFACE LOWS WILL DEVELOP ACROSS THE NORTHERN
AND CENTRAL ROCKIES BRINGING A PREDOMINATELY SOUTHEAST SURFACE
FLOW ALLOWING FOR INCREASING LOW-LEVEL MOISTURE ACROSS THE AREA
THROUGH WEDNESDAY. MODELS INCLUDING THE HRRR BRING A VORT MAX OVER
OUR AREA TODAY RESULTING IN SHOWERS AND ISOLATED THUNDERSTORMS.
SHEAR IS A BIT BETTER TODAY BUT STILL NOT IMPRESSIVE. CAPES ARE
ALSO SLIGHTLY BETTER TODAY AND MORE WIDESPREAD SO THUNDERSTORM
CHANCES WILL BE BETTER TODAY THAN TUESDAY. PRE-FRONTAL WARMING
TODAY WILL ALLOW TEMPERATURES TO WARM WELL INTO THE 70S TO AROUND
80 DEGREES
A COLD FRONT WILL MOVE ACROSS THE FORECAST AREA WEDNESDAY MORNING
USHERING IN GUSTY NORTHWEST WINDS BY AFTERNOON ALONG WITH A CHANCE
FOR SHOWERS AND ISOLATED THUNDERSTORMS. TEMPERATURES WILL BE MUCH
COOLER WITH READINGS ONLY IN THE LOWER TO MIDDLE 60S SO
INSTABILITY FOR THUNDERSTORMS WILL NOT BE AS GOOD AS TODAY. A
STRONGER DISTURBANCE AND UPPER LOW WILL MOVE NORTHEAST OUT OF
WYOMING WEDNESDAY INTO WEDNESDAY NIGHT. MODELS SHOW GOOD WRAP-
AROUND MOISTURE WITH THIS ALONG WITH DECENT QPF AMOUNTS. AS A
RESULT...HAVE INCREASED POPS INTO THE LIKELY AND CATEGORICAL RANGE
DURING THIS TIME FROM CUSTER AND POWDER RIVER COUNTIES EASTWARD.
ELSEWHERE...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS. HOOLEY
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
LATEST MODEL RUNS HAVE CONTINUED TO KEEP THE BULK OF THE ENERGY
AND MOISTURE OUT OF THE THE AREA. MODELS HAVE CONTINUED TO TRACK
WELL WITH EACH OTHER...WITH THE 00Z DATA HAVING MORE OF A CLOSED
LOW EJECTING FROM THE GREAT BASIN THIS WEEKEND...BUT IT TRACKS
MORE INTO THE CENTRAL PLAINS. THIS HAS THE EFFECT OF KEEPING THE
BULK OF THE MOISTURE AND ENERGY SOUTH OF MONTANA. CONTINUE TO SEE
DIFFLUENT FLOW ALOFT ACROSS THE AREA THIS WEEKEND...ALONG WITH
SOME MID-LEVEL MOISTURE. THIS WILL KEEP AT LEAST A CHANCE OF LIGHT
SCATTERED PRECIP ACROSS THE AREA. HAVE TRENDED POPS DOWN SOME
GIVEN THE TREND AWAY FROM A MORE FAVORABLE SOLUTION. THE COLUMN
IS NOT OVERLY SATURATED...WITH PRECIPITABLE WATER VALUES ONLY
AROUND A HALF INCH. THE POTENTIAL FOR MUCH ACCUMULATION REMAINS
LOW. WITH THE MID LEVEL MOISTURE...MUCH OF THE EXTENDED PERIOD
WILL BE CLOUDY...THUS COOLER. TEMPERATURES CONTINUE BE IN THE 50S
FOR HIGHS. REIMER
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL THIS MORNING. ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS WILL DEVELOP FROM ROUNDUP TO KBIL TO
KSHR W THIS AFTERNOON...AND CONTINUE INTO EARLY EVENING. THE
PRECIPITATION WILL PRODUCE MVFR/IFR CONDITIONS. AREAS OF MOUNTAIN
OBSCURATION WILL DEVELOP THIS AFTERNOON. PRECIPITATION WILL BECOME
MORE WIDESPREAD THIS EVENING AS A COLD FRONT PUSHES INTO THE AREA
BRINGING A WIND SHIFT TO THE NW AT KLVM BY 06Z. THE THREAT FOR
THUNDER WILL DECREASE LATE THIS EVENING. SCATTERED SHOWERS ARE
EXPECTED LATE TONIGHT. MVFR TO IFR CONDITIONS WILL CONTINUE WITH
THE PRECIPITATION TONIGHT...WITH AREAS OF MOUNTAIN OBSCURATION.
THE COLD FRONT WILL REACH KMLS BY 12Z WED. ARTHUR
&&
.PRELIMINARY POINT TEMP/POPS...
TDY WED THU FRI SAT SUN MON
-------------------------------------------------------
BIL 079 049/059 040/053 040/053 039/051 038/059 040/060
2/T 43/W 22/W 24/W 55/W 43/W 32/W
LVM 076 043/061 036/050 034/048 034/050 034/059 035/060
3/T 64/W 35/W 35/W 55/W 43/W 33/W
HDN 082 050/061 042/056 038/057 039/053 037/059 035/062
1/B 34/W 22/W 23/W 55/W 43/W 32/W
MLS 079 051/060 041/055 037/056 038/054 037/057 038/061
1/B 38/W 42/W 12/W 44/W 43/W 32/W
4BQ 075 051/061 043/055 035/055 039/052 035/053 034/059
1/B 48/T 42/W 12/W 55/W 44/W 32/W
BHK 073 050/060 042/054 034/054 035/052 034/054 031/057
1/N 39/T 72/W 12/W 44/W 33/W 22/W
SHR 075 048/054 037/053 035/054 038/050 035/051 032/058
2/T 45/W 43/W 34/W 55/W 54/W 33/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
354 AM MDT TUE MAY 5 2015
.SHORT TERM...VALID FOR TDY AND WED...
UNSETTLED WEATHER BEGINS TODAY AND WILL CONTINUE RIGHT THROUGH
THE REMAINDER OF THE WEEK. AN UPPER LOW AND TROUGH WILL MOVE ONTO
THE PACIFIC NORTHWEST COAST TODAY AND REMAIN STATIONARY OR SLOWLY
SHIFT SOUTHEAST TOWARD THE GREAT BASIN AREA DURING THE DAY
WEDNESDAY. THIS WILL ALLOW A SOUTHWEST FLOW ALOFT TO BEGIN TO
DEVELOP OVER OUR AREA TODAY AND ESPECIALLY BE IN PLACE FOR
WEDNESDAY. SEVERAL SURFACE LOWS WILL DEVELOP ACROSS THE NORTHERN
AND CENTRAL ROCKIES BRINGING A PREDOMINATELY SOUTHEAST SURFACE
FLOW ALLOWING FOR INCREASING LOW-LEVEL MOISTURE ACROSS THE AREA
THROUGH WEDNESDAY. MODELS INCLUDING THE HRRR BRING A VORT MAX OVER
OUR AREA TODAY RESULTING IN SHOWERS AND ISOLATED THUNDERSTORMS.
SHEAR IS A BIT BETTER TODAY BUT STILL NOT IMPRESSIVE. CAPES ARE
ALSO SLIGHTLY BETTER TODAY AND MORE WIDESPREAD SO THUNDERSTORM
CHANCES WILL BE BETTER TODAY THAN TUESDAY. PRE-FRONTAL WARMING
TODAY WILL ALLOW TEMPERATURES TO WARM WELL INTO THE 70S TO AROUND
80 DEGREES.
A COLD FRONT WILL MOVE ACROSS THE FORECAST AREA WEDNESDAY MORNING
USHERING IN GUSTY NORTHWEST WINDS BY AFTERNOON ALONG WITH A CHANCE
FOR SHOWERS AND ISOLATED THUNDERSTORMS. TEMPERATURES WILL BE MUCH
COOLER WITH READINGS ONLY IN THE LOWER TO MIDDLE 60S SO
INSTABILITY FOR THUNDERSTORMS WILL NOT BE AS GOOD AS TODAY. A
STRONGER DISTURBANCE AND UPPER LOW WILL MOVE NORTHEAST OUT OF
WYOMING WEDNESDAY INTO WEDNESDAY NIGHT. MODELS SHOW GOOD WRAP-
AROUND MOISTURE WITH THIS ALONG WITH DECENT QPF AMOUNTS. AS A
RESULT...HAVE INCREASED POPS INTO THE LIKELY AND CATEGORICAL RANGE
DURING THIS TIME FROM CUSTER AND POWDER RIVER COUNTIES EASTWARD.
ELSEWHERE...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS. HOOLEY
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
LATEST MODEL RUNS HAVE CONTINUED TO KEEP THE BULK OF THE ENERGY
AND MOISTURE OUT OF THE THE AREA. MODELS HAVE CONTINUED TO TRACK
WELL WITH EACH OTHER...WITH THE 00Z DATA HAVING MORE OF A CLOSED
LOW EJECTING FROM THE GREAT BASIN THIS WEEKEND...BUT IT TRACKS
MORE INTO THE CENTRAL PLAINS. THIS HAS THE EFFECT OF KEEPING THE
BULK OF THE MOISTURE AND ENERGY SOUTH OF MONTANA. CONTINUE TO SEE
DIFFLUENT FLOW ALOFT ACROSS THE AREA THIS WEEKEND...ALONG WITH
SOME MID-LEVEL MOISTURE. THIS WILL KEEP AT LEAST A CHANCE OF LIGHT
SCATTERED PRECIP ACROSS THE AREA. HAVE TRENDED POPS DOWN SOME
GIVEN THE TREND AWAY FROM A MORE FAVORABLE SOLUTION. THE COLUMN
IS NOT OVERLY SATURATED...WITH PRECIPITABLE WATER VALUES ONLY
AROUND A HALF INCH. THE POTENTIAL FOR MUCH ACCUMULATION REMAINS
LOW. WITH THE MID LEVEL MOISTURE...MUCH OF THE EXTENDED PERIOD
WILL BE CLOUDY...THUS COOLER. TEMPERATURES CONTINUE BE IN THE 50S
FOR HIGHS. REIMER
&&
.AVIATION...
VFR CONDITIONS EXPECT THROUGH MUCH OF THE NEXT 24. SOME SHOWERS
AND THUNDERSTORMS WILL DEVELOP OVER THE MOUNTAINS AND WILL MOVE
EAST IN THE ADJACENT PLAINS. LATEST HIRES MODELS SHOW ACTIVITY
STAYING WEST OF BILLINGS...LIMITING MOST THUNDERSTORM ACTIVITY TO
LIVINGSTON AND SHERIDAN. LOW LEVEL WIND SHEER WILL CONTINUE
AROUND MILES CITY UNTIL AROUND MID MORNING BEFORE SURFACE WIND
BEGIN TO INCREASE. REIMER
&&
.PRELIMINARY POINT TEMP/POPS...
TDY WED THU FRI SAT SUN MON
-------------------------------------------------------
BIL 079 049/059 040/053 040/053 039/051 038/059 040/060
2/T 43/W 22/W 24/W 55/W 43/W 32/W
LVM 076 043/061 036/050 034/048 034/050 034/059 035/060
3/T 64/W 35/W 35/W 55/W 43/W 33/W
HDN 082 050/061 042/056 038/057 039/053 037/059 035/062
1/B 34/W 22/W 23/W 55/W 43/W 32/W
MLS 079 051/060 041/055 037/056 038/054 037/057 038/061
1/U 38/W 42/W 12/W 44/W 43/W 32/W
4BQ 075 051/061 043/055 035/055 039/052 035/053 034/059
1/B 48/T 42/W 12/W 55/W 44/W 32/W
BHK 073 050/060 042/054 034/054 035/052 034/054 031/057
1/N 39/T 72/W 12/W 44/W 33/W 22/W
SHR 075 048/054 037/053 035/054 038/050 035/051 032/058
2/T 45/W 43/W 34/W 55/W 54/W 33/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
327 AM MDT TUE MAY 5 2015
.SYNOPSIS...
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY AS
AN UPPER LEVEL DISTURBANCE PASSES OVERHEAD. THE STRONGEST STORMS
WILL BE FOUND ACROSS THE FAR EASTERN PLAINS WHERE LARGE
HAIL...DAMAGING WINDS AND HEAVY RAIN WILL BE A CONCERN. AFTER
TODAY...MAINLY DRY AND WINDY CONDITIONS ARE IN STORE THROUGH FRIDAY.
HOWEVER...A FEW THUNDERSTORMS WILL BE POSSIBLE EACH AFTERNOON
ACROSS THE FAR EASTERN PLAINS ALONG THE DRYLINE. THE NEXT STORM
SYSTEM LOOKS TO CROSS THE STATE ON SATURDAY...WHICH MAY INCREASE
PRECIPITATION CHANCES ACROSS THE WEST. OTHERWISE... TEMPERATURES
WILL REMAIN NEAR TO BELOW NORMAL FOR THE NEXT SEVEN DAYS.
&&
.DISCUSSION...
SHOWERS AND A FEW THUNDERSTORMS CONTINUE THIS MORNING ACROSS EASTERN
NM AHEAD OF UPPER LEVEL LOW WHICH IS NOW CENTERED IN THE VICINITY OF
FLAGSTAFF. THIS CURRENT ACTIVITY SHOULD LARGELY PUSH EAST OF THE
TEXAS BORDER BY 12-14Z AND ALLOW FOR A SHORT BREAK BEFORE THE NEXT
ROUND BEGINS. WITH STRONG FORCING AND LITTLE TO NO INHIBITION...
STORMS SHOULD DEVELOP EARLY...PERHAPS BY 17Z...ALONG OR JUST EAST OF
HIGHER TERRAIN AND/OR ALONG REMNANT BOUNDARIES. BEST INSTABILITY
REMAINS ACROSS THE FAR EASTERN PLAINS WHERE CAPE VALUES MAY APPROACH
2000 J/KG. THUS STORMS MAY INITIATE NEAR THE CENTRAL MTN CHAIN...BUT
INCREASE IN STRENGTH AS THEY MOVE INTO BETTER MOISTURE AND
INSTABILITY. LOW LEVEL WINDS LOOK TO VEER TO AROUND TO THE SW BY
EARLY AFTERNOON AS THE TROUGH AXIS MOVES EASTWARD AND DRIER WESTERLY
FLOW MOVES INTO THE AREA. PRIOR TO THE DRY AIR MOVING IN...PWATS
WILL REMAIN NEAR 1 INCH...OR BETTER THAN 200 PERCENT OF NORMAL FOR
THIS TIME OF YEAR. THUS...A HEAVY RAIN THREAT WILL CONTINUE TO EXIST
WITH THESE STORMS. AREAS THAT HAVE ALREADY RECEIVED SIGNFICANT
AMOUNTS OF RAIN WILL BE THE MOST SUSCEPTIBLE TO ADDITIONAL FLOODING.
THIS INCLUDES THE CLOVIS AREA WHERE UP TO 5 INCHES OF RAIN FELL
YESTERDAY. THE FLASH FLOOD WATCH REMAINS INTACT THROUGH 00Z AND ANY
SEVERE WEATHER IS MOST LIKELY TO OCCUR BETWEEN NOON AND 6PM.
MEANWHILE ACROSS WESTERN AND CENTRAL NM...ANOTHER ROUND OF SCATTERED
TO NUMEROUS THUNDERSTORMS WILL DEVELOP. THIS AREA WILL BE UNDER THE
COLD CORE OF THE LOW...THUS A FEW STORMS MAY CONTAIN SOME SMALL HAIL
AND HEAVY RAIN. A COLD CORE FUNNEL IS ALSO NOT OUT OF THE QUESTION.
BRIEF SHORTWAVE RIDGING WILL OCCUR ON WEDNESDAY BEFORE SOUTHWESTERLY
FLOW INCREASES AHEAD OF THE NEXT STORM SYSTEM. A 996 MB SURFACE LOW
ACROSS SE CO WILL ALLOW FOR WINDS TO INCREASE ACROSS THE PLAINS.
OTHERWISE MUCH DRIER CONDITIONS AS THE DRY SLOT MOVES OVERHEAD AND
SOME DRY AIR MIXES DOWN TO THE SURFACE. BEST CHANCE FOR A FEW STORMS
WILL BE ACROSS THE NW OR NC NM.
THE DRYLINE WILL SLOSH BACK WESTWARD WEDNESDAY NIGHT AND THIS WILL
BE A THEME FOR THE REST OF THE WEEK. THE NEXT LOW PRESSURE SYSTEM
LOOKS TO DIVE MUCH FURTHER SOUTH THAN PREVIOUSLY INDICATED. IT
APPEARS IT MAY ACTUALLY REMAIN A CLOSED LOW AS IT CROSSES NORTHERN NM
ON SATURDAY. IF THE LOW DOES INDEED DIVE THAT FAR SOUTH...EXPECT THE
DRYLINE TO RETREAT WESTWARD INTO EASTERN NM EACH NIGHT AND THEN MIX
BACK EASTWARD EACH DAY. WITH THAT...WILL COME A CHANCE FOR A FEW
STORMS NEAR THE TEXAS BORDER EACH AFTERNOON. ELSEWHERE...IT WILL BE
MAINLY DRY AND BREEZY UNTIL SATURDAY WHEN BETTER CHANCES OF PRECIP
WILL EXIST AS LOW SHIFTS OVERHEAD.
34
&&
.FIRE WEATHER...
NO WIDESPREAD FIRE WEATHER CONCERNS THROUGH THE FORECAST PERIOD.
SMALL AREAS OF MARGINAL CRITICAL FIRE WEATHER CONDITIONS ARE
POSSIBLE FRIDAY AND SATURDAY.
IT WAS A WET MONDAY ACROSS THE FORECAST AREA...ESPECIALLY IN THE
EAST. AROUND FIVE INCHES OF RAIN FELL AT THE CANNON AIR FORCE BASE.
THE UPPER LOW CAUSING ALL THIS RAIN IS NOW OVER AZ. IT WILL TRACK
NORTHEAST ACROSS THE FOUR CORNERS AREA TODAY. A DRY SLOT IS EVIDENT
ON SATELLITE IMAGES ACROSS SOUTHWEST NM AND IT WILL CONTINUE ACROSS
SOUTHERN NM TODAY. SHOWER AND THUNDERSTORM COVERAGE WILL BE LESS
TODAY COMPARED TO MONDAY. BUT PLENTY OF LOW LEVEL MOISTURE IS STILL
AROUND ALONG WITH A VERY UNSTABLE AIRMASS...ESPECIALLY IN THE EAST.
SO ANOTHER ACTIVE DAY ON TAP WITH THE POTENTIAL FOR SEVERE STORMS
NEAR THE TX BORDER. SOME OF THE RAIN WILL BE HEAVY AS WELL WITH
FLASH FLOODING A CONCERN...ESPECIALLY FOR PLACES HIT HARD MONDAY.
SOME OF THE STORMS WILL PRODUCE SMALL HAIL AS TEMPERATURES ALOFT
WILL BE QUITE COLD FOR EARLY MAY. MIN RH VALUES WILL ONLY DROP TO
BETWEEN 40 AND 60 PERCENT TODAY WHILE VENT RATES WILL BE MOSTLY
EXCELLENT.
A DRYING TREND REMAINS ON TRACK FOR THE REST OF THE WEEK. HIGH
TEMPERATURES WILL WARM TO WITHIN SIX OR SEVEN DEGREES EITHER SIDE
OF NORMAL WEDNESDAY THROUGH FRIDAY. THERE WILL STILL BE SHOWERS AND
A FEW STORMS OVER THE NORTHWEST THIRD OF THE STATE WEDNESDAY AND
NEAR THE TX BORDER ON THURSDAY ALONG A POTENTIAL DRYLINE.
MODELS CONTINUE TO TREND FARTHER SOUTH WITH A UNSEASONABLY DEEP
CLOSED LOW DROPPING SOUTH THROUGH CALIFORNIA THURSDAY INTO FRIDAY.
INCREASING SOUTHWEST WINDS AHEAD OF THE STORM MAY RESULT IN A FEW
HOURS OF CRITICAL CONDITIONS FOR THE LOWER RIO GRANDE VALLEY FRIDAY
AFTERNOON...AND BORDERLINE CRITICAL CONDITIONS OVER A SMALL AREA OF
THE EASTERN PLAINS SATURDAY. VENTILATION RATES WILL GENERALLY REMAIN
IN THE GOOD TO EXCELLENT RANGE DURING THIS TIME.
THE ABOVE MENTIONED STORM WILL BRING COOLER AND WETTER CONDITIONS
BACK TO NM FOR FRIDAY NIGHT INTO THE WEEKEND. THE STORM SHOULD LIFT
NORTHEAST INTO CO SUNDAY...BRINGING SOME DRYING AND WARMING TO THE
AREA. THIS TREND WILL CONTINUE ON MONDAY. AN ACTIVE DRY LINE MIGHT
SET UP TUESDAY ACROSS THE EAST.
CHJ
&&
.AVIATION...
06Z TAF CYCLE
A SLOW MOVING UPPER LEVEL LOW PRESSURE SYSTEM WILL CONTINUE TO
STEER BANDS OF SHOWERS AND THUNDERSTORMS NORTH AND NORTHEASTWARD
ACROSS N AND E PARTS OF THE FORECAST AREA THROUGH THE OVERNIGHT
HOURS. THE TRUSTED HRRR MODELS DEPICTION OF DECREASING ACTIVITY
ACROSS SW AND CENTRAL AREAS APPEARS TO BE COMING TRUE. AREAS OF
LOW CLOUDS AND POSSIBLY SOME FOG ARE EXPECTED TO BECOME GRADUALLY
MORE WIDESPREAD THROUGH THE NIGHT ACROSS MUCH OF THE PLAINS.
THOUGH ITS FORMATION COULD BE A BIT PATCHY DUE TO SOME MID LEVEL
CLOUD COVER. MODELS AGREE ON A DOWNTICK IN CONVECTIVE ACTIVITY
TUESDAY MORNING AS LOW CLOUDS GRADUALLY BREAK UP IN THE EAST. THEN
ANOTHER ROUND OF SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS
IS EXPECTED IN THE AFTERNOON AND EVENING WITH HIGHEST
PROBABILITIES ACROSS NORTHERN AREAS.
44
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 66 46 71 41 / 60 50 20 10
DULCE........................... 59 39 65 35 / 70 60 40 30
CUBA............................ 60 41 66 38 / 60 50 20 20
GALLUP.......................... 61 39 67 34 / 50 40 10 10
EL MORRO........................ 58 38 64 35 / 60 30 10 10
GRANTS.......................... 62 38 68 33 / 50 30 5 5
QUEMADO......................... 60 37 67 34 / 50 20 5 5
GLENWOOD........................ 69 44 74 42 / 30 10 0 5
CHAMA........................... 58 36 59 31 / 70 60 40 20
LOS ALAMOS...................... 60 44 67 44 / 70 40 20 10
PECOS........................... 58 43 65 42 / 70 30 10 10
CERRO/QUESTA.................... 60 38 64 34 / 70 40 20 20
RED RIVER....................... 50 35 52 31 / 70 50 30 20
ANGEL FIRE...................... 54 35 58 28 / 70 40 20 10
TAOS............................ 61 38 65 34 / 60 40 20 10
MORA............................ 57 42 64 39 / 70 30 10 10
ESPANOLA........................ 63 45 71 43 / 60 30 10 10
SANTA FE........................ 60 44 66 42 / 60 30 10 5
SANTA FE AIRPORT................ 65 43 70 40 / 60 30 10 5
ALBUQUERQUE FOOTHILLS........... 67 48 73 47 / 40 30 5 5
ALBUQUERQUE HEIGHTS............. 69 49 74 50 / 40 20 0 5
ALBUQUERQUE VALLEY.............. 70 47 76 46 / 40 20 0 5
ALBUQUERQUE WEST MESA........... 69 48 75 47 / 40 30 0 5
LOS LUNAS....................... 71 47 78 45 / 30 20 0 5
RIO RANCHO...................... 67 49 74 48 / 50 30 5 5
SOCORRO......................... 71 49 79 48 / 30 20 0 5
SANDIA PARK/CEDAR CREST......... 64 44 71 44 / 50 40 10 5
TIJERAS......................... 66 44 73 44 / 40 30 5 5
MORIARTY/ESTANCIA............... 64 40 69 37 / 40 20 0 5
CLINES CORNERS.................. 63 41 68 40 / 50 20 0 5
GRAN QUIVIRA.................... 65 44 70 44 / 40 20 0 5
CARRIZOZO....................... 69 48 74 48 / 20 10 0 5
RUIDOSO......................... 65 45 71 45 / 30 10 0 5
CAPULIN......................... 61 44 69 43 / 70 30 10 10
RATON........................... 64 42 72 40 / 70 20 5 10
SPRINGER........................ 65 44 74 41 / 60 20 5 5
LAS VEGAS....................... 61 44 69 39 / 60 20 5 5
CLAYTON......................... 64 47 79 48 / 80 30 5 5
ROY............................. 64 46 73 44 / 60 20 5 5
CONCHAS......................... 70 52 79 50 / 60 20 0 5
SANTA ROSA...................... 70 50 78 48 / 60 20 0 5
TUCUMCARI....................... 72 53 81 51 / 70 20 0 5
CLOVIS.......................... 71 49 78 51 / 70 20 0 10
PORTALES........................ 72 51 79 52 / 70 20 0 10
FORT SUMNER..................... 72 51 80 51 / 60 20 0 5
ROSWELL......................... 79 51 84 50 / 30 10 0 5
PICACHO......................... 73 49 79 49 / 30 10 0 5
ELK............................. 68 47 74 47 / 30 10 0 5
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR THE FOLLOWING ZONES...
NMZ535>538.
&&
$$
34
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1154 PM MDT MON MAY 4 2015
.AVIATION...
06Z TAF CYCLE
A SLOW MOVING UPPER LEVEL LOW PRESSURE SYSTEM WILL CONTINUE TO
STEER BANDS OF SHOWERS AND THUNDERSTORMS NORTH AND NORTHEASTWARD
ACROSS N AND E PARTS OF THE FORECAST AREA THROUGH THE OVERNIGHT
HOURS. THE TRUSTED HRRR MODELS DEPICTION OF DECREASING ACTIVITY
ACROSS SW AND CENTRAL AREAS APPEARS TO BE COMING TRUE. AREAS OF
LOW CLOUDS AND POSSIBLY SOME FOG ARE EXPECTED TO BECOME GRADUALLY
MORE WIDESPREAD THROUGH THE NIGHT ACROSS MUCH OF THE PLAINS.
THOUGH ITS FORMATION COULD BE A BIT PATCHY DUE TO SOME MID LEVEL
CLOUD COVER. MODELS AGREE ON A DOWNTICK IN CONVECTIVE ACTIVITY
TUESDAY MORNING AS LOW CLOUDS GRADUALLY BREAK UP IN THE EAST. THEN
ANOTHER ROUND OF SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS
IS EXPECTED IN THE AFTERNOON AND EVENING WITH HIGHEST
PROBABILITIES ACROSS NORTHERN AREAS.
44
&&
.PREV DISCUSSION...1027 PM MDT MON MAY 4 2015...
.UPDATE...
RATHER MODEST UPDATE TO LOWER POPS SOME ACROSS PARTS OF THE WEST
AND FAR NE FOR REST OF PRE MIDNIGHT PERIOD...BUT NOT MANY CHANGES
AFTER MIDNIGHT. LOWERED QPF SHARPLY FOR REST OF PRE MIDNIGHT
PERIOD DUE MOST TO THERE BEING UNDER TWO HOURS LEFT TIL THEN...BUT
ALLOWED FOR RADAR TRENDS AS WELL. DROPPED LOW TEMPS A DEGREE OR
TWO PORTIONS OF CENTRAL NM AND IMMEDIATELY ADJACENT LOCALES...ALSO
FAR NW. FAR E CENTRAL NM...WHERE MOST OF REPORTED SIGNIFICANT
FLOODING HAS OCCURRED WILL BE SEEING MUCH LESS INTENSE OFF AND ON
RAIN REST OF THE NIGHT.
43
&&
.PREV DISCUSSION...330 PM MDT MON MAY 4 2015...
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO IMPACT THE STATE
THROUGH TUESDAY AS AN UPPER LEVEL LOW PRESSURE SYSTEM...CURRENTLY
OVER ARIZONA...MOVES SLOWLY EAST ACROSS THE REGION. MOST AREAS WILL
SEE GOOD CHANCES FOR WETTING RAINS...BUT LOCALES BETWEEN THE
CENTRAL MOUNTAIN CHAIN AND THE TEXAS BORDER WILL HAVE THE BEST
CHANCES WITH THE POTENTIAL FOR FLASH FLOODING AND SOME HAIL. LOOK
FOR MOSTLY DRY...WARM AND BREEZY TO LOCALLY WINDY CONDITIONS TO
PREVAIL FROM WEDNESDAY THROUGH SATURDAY AS ANOTHER UPPER LEVEL LOW
PRESSURE SYSTEM GRADUALLY APPROACHES FROM THE WEST. TEMPERATURES
WILL TREND DOWN OVER THE WEEKEND AS THE UPPER LEVEL LOW PRESSURE
SYSTEM PUSHES A PACIFIC COLD FRONT THROUGH.
&&
.DISCUSSION...
MOISTURE ADVECTION AND DESTABILIZATION OF THE ATMOSPHERE WITH THE
APPROACH OF THE UPPER LOW...CURRENTLY OVER ARIZONA...IS RESULTING
IN THUNDERSTORMS BREAKING-OUT ACROSS MUCH OF THE AREA. THROUGH 3
PM MDT...THE MOST ROBUST THUNDERSTORMS HAVE BEEN ACROSS THE
EASTERN PLAINS WHERE SEVERAL REPORTS OF HAIL UP TO QUARTER SIZE
AND RAIN AMOUNTS IN EXCESS OF ONE INCH IN 30 MINUTES HAVE BEEN
REPORTED. MOISTURE ADVECTION IS FORECAST TO CONTINUE INTO THE
EVENING HOURS...WITH PWATS EXCEEDING ONE INCH ACROSS SOUTHEAST
PORTIONS OF OUR AREA WHICH WOULD BE NEAR THE 99TH PERCENTILE IN
TERMS OF MAY PWAT CLIMATOLOGY. AT THIS POINT...THE FLASH FLOOD
THREAT WOULD APPEAR LIMITED...BUT SOME MERGING/ORGANIZATION OF
STORMS IS FORECAST TO OCCUR OVERNIGHT AND WILL INCREASE THE FLASH
FLOOD THREAT OVER THE WATCH AREA. ELSEWHERE...THE FLASH FLOOD
THREAT SHOULD BE LOCALIZED...THOUGH SOAKING RAINS ARE LIKELY ACROSS
CENTRAL AND NORTHERN PORTIONS OF NEW MEXICO.
ANOTHER HEALTHY ROUND OF STORMS FORECAST TUESDAY AS THE UPPER LOW
MOVES OVERHEAD...WITH THE BEST CHANCES FOR DEEP...PERHAPS
SEVERE..CONVECTION NEAR THE TEXAS BORDER WHERE THE SPC SHOWS A
SLIGHT RISK FOR SEVERE STORMS IN THE DAY 2 CONVECTIVE OUTLOOK.
THAT SAID...CONVECTION IS FORECAST TO SHIFT RAPIDLY INTO THE TEXAS
PANHANDLE TUESDAY AFTERNOON...SO THE SEVERE THREAT MAY BE LIMITED
TO A FEW HOURS DURING THE AFTERNOON. ELSEWHERE...HAIL-PRODUCING
STORMS ARE FORECAST BY AFTERNOON...ESPECIALLY IN THE MOUNTAINS...
WITH THE POTENTIAL FOR SEVERAL INCHES OF HAIL ACCUMULATION THOUGH
ACTUAL HAIL SIZE SHOULD BE LESS THAN ONE INCH. TUESDAY WILL BE A
"COOL" DAY WITH HIGHS BELOW NORMAL AREAWIDE.
A DRYING/WARMING TREND TO KICK-OFF WEDNESDAY AND CONTINUE THROUGH
THE END OF THE WORK WEEK WITH BREEZY TO LOCALLY WINDY CONDITIONS.
A FEW SHOWERS AND THUNDERSTORMS ARE FORECAST EACH DAY...MAINLY
ACROSS THE WESTERN AND NORTHERN HIGH TERRAIN...BUT GIVEN A
SIGNIFICANT DOWNTREND IN PWATS WETTING RAINS WILL BE HARD TO COME-
BY. SOME POTENTIAL EXISTS FOR A DRYLINE THUNDERSTORM OR TWO
BETWEEN WEDNESDAY NIGHT AND FRIDAY ACROSS THE FAR SOUTHEAST...
DEPENDENT ON THE EXTENT OF THE DRYLINE SLOSHING WESTWARD.
A COOLING TREND FORECAST OVER THE WEEKEND AS THE EASTWARD
ADVANCING UPPER LOW PUSHES A PACIFIC COLD FRONT THROUGH. THE 12Z
MODEL SUITE TRENDED FURTHER SOUTH WITH THE BOTTOMING OF THE UPPER LOW
LATER THIS WEEK AND PUSHES IT FURTHER EAST BEFORE PULLING IT OUT
TO THE NORTHEAST COMPARED TO PREVIOUS RUNS. IF THIS TREND
CONTINUES THEN THIS FEATURE MAY BE MORE OF A WEATHER-MAKER FOR US
THAN WHAT IS CURRENTLY IN OUR FORECAST.
11
&&
.FIRE WEATHER...
ATMOSPHERIC LIFT ASSOCIATED WITH UPPER LOW/TROUGH OVER WESTERN
ARIZONA DRAWING UP PLENTIFUL MID LEVEL SUBTROPICAL MOISTURE TO
PRODUCE SCATTERED SHOWERS AND THUNDERSTORMS OVER MUCH OF THE AREA.
LOW LEVEL GULF MOISTURE SURGED NORTHWARD LAST NIGHT AND THIS MORNING
ON A LOW LEVEL JET CENTERED OVER FAR WEST TX AND SE NM. SHOWERS AND
STORMS WILL CONTINUE WELL INTO THE EVENING HOURS AS LIFT AHEAD OF
THE UPPER LOW REMAINS OVER NEW MEXICO. STRONG TO SEVERE STORMS OVER
THE EASTERN PLAINS WILL CONTINUE OVERNIGHT. HEAVY RAINFALL AMOUNTS
ARE LIKELY OVER THE EAST-CENTRAL AND SOUTHEAST PLAINS.
ABOVE MENTIONED UPPER LOW/TROUGH SLIDES NORTHEASTWARD TO NEAR THE
FOUR CORNERS BY TUESDAY MORNING. COLD POOL OF AIR ALOFT WILL COMBINE
WITH DAYTIME HEATING AND RESIDUAL MOISTURE TO GENERATE ANOTHER ROUND
OF SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. MAY OF THE
STORMS WILL LIKELY PRODUCE SMALL HAIL AS TEMPERATURES ALOFT WILL BE
QUITE COLD FOR EARLY MAY. WIDESPREAD WETTING RAINS REMAIN ON TRACK
BETWEEN THIS AFTERNOON AND TUESDAY EVENING OVER MUCH OF CENTRAL AND
NORTHERN NEW MEXICO.
DRIER BUT COOLER THAN AVERAGE TEMPERATURES REMAIN ON TRACK FOR
WEDNESDAY. WEATHER PREDICTION MODELS ARE IN GOOD AGREEMENT THAT LOW
LEVEL SOUTHERLY WINDS WILL INCREASE THURSDAY...RESULTING IN SLIGHT
WARMING. MODELS ARE TRENDING FARTHER SOUTH WITH A UNSEASONABLY DEEP
CLOSED LOW DROPPING SOUTH THROUGH CALIFORNIA WEDNESDAY NIGHT AND
THURSDAY. ANY FARTHER SOUTH AND THE FLOW ALOFT COULD BACK ENOUGH TO
DRAW UP SUBTROPICAL MOISTURE ONCE AGAIN...RESULTING IN MORE
PRECIPITATION THAN WIND. AT THIS TIME...HOWEVER...CURRENT MODEL
SOLUTIONS WOULD RESULT IN INCREASING SOUTHWEST WINDS AND A FEW HOURS
OF CRITICAL CONDITIONS FOR THE LOWER RIO GRANDE VALLEY FRIDAY
AFTERNOON. VENTILATION RATES WILL GENERALLY BE IN GOOD TO EXCELLENT
RANGE DURING THE NEXT SEVEN DAYS.
33
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH TUESDAY AFTERNOON FOR THE FOLLOWING
ZONES...NMZ535>538.
&&
$$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
346 PM EDT TUE MAY 5 2015
.SYNOPSIS...
A FRONTAL ZONE WILL REMAIN NEARLY STATIONARY OVER THE MID-ATLANTIC
STATES TONIGHT THROUGH WEDNESDAY. SOME SHOWERS WILL MOVE ALONG AND
NORTH OF THE FRONT BRINGING A CHANCE FOR SOME RAIN TO SOUTHERN NEW
YORK AND NORTHERN PENNSYLVANIA. THE BEST CHANCE FOR RAIN WILL BE
TONIGHT AND EARLY WEDNESDAY. HIGH PRESSURE WILL RETURN ON THURSDAY
BRINGING WARM DRY WEATHER. AN APPROACHING COLD FRONT MAY TRIGGER A
FEW SCATTERED SHOWERS OR THUNDERSTORMS LATER FRIDAY AFTERNOON.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY/...
MAIN FORECAST QUESTION FOR TONIGHT WILL BE THE IMPACT OF A SHORT
WAVE AND ASSOCIATED AREA OF RAIN MOVING EAST FROM THE SOUTHERN
GREAT LAKES TOWARD NORTHERN PENNSYLVANIA AND SOUTHERN NY. THE
NAM/GFS/ECMWF AND SREF ARE ALL IN REASONABLY GOOD AGREEMENT THAT
THE BEST CHANCE OF RAIN WILL BE ACROSS NORTHERN PA THIS EVENING
WITH LOWER CHANCES FARTHER NORTH AND EAST OVERNIGHT. THE IDEA THAT
RAIN MAY STRUGGLE TO REACH VERY FAR EAST OF I-81 IN NY STATE
APPEARS REASONABLE GIVEN THAT SURFACE HIGH PRESSURE WILL BE
BUILDING SOUTHEAST TOWARD THAT AREA OVERNIGHT. LATEST RADAR
ANIMATIONS ARE ALREADY INDICATING A SLUG OF MODERATE TO HEAVY RAIN
MOVING FROM SOUTHERN ONTARIO ACROSS SW NY AND NORTHWEST PA. THE
LAST FEW RUNS OF THE HRRR INDICATE THAT SOME OF THIS RAIN WILL
MOVE ACROSS SOUTHERN NY THROUGH MID- EVENING REACHING THE
CATSKILLS BEFORE MIDNIGHT. THIS SCENARIO IS A BIT FARTHER NORTH
AND EAST THAN SOME OF THE LOWER-RESOLUTION OPERATIONAL MODELS.
BASED ON ALL OF THIS HAVE GONE WITH LIKELY POPS THIS EVENING INTO
THE OVERNIGHT FOR NORTHERN PA AND THE SOUTHERN TIER OF NY WITH
JUST CHC POPS FARTHER NORTH. THUNDER CHANCES LOOK LOW WITH NO
INSTABILITY SHOWING UP ON ANY MODEL FORECAST SOUNDINGS.
&&
.SHORT TERM /6 AM WEDNESDAY THROUGH FRIDAY/...
SHOWERS WILL BE WEAKENING AND PUSHING SOUTH AND SOUTHEAST EARLY
WEDNESDAY. CLOUDS WILL LINGER THROUGH MUCH OF THE DAY ACROSS
NORTHERN PA AND SOUTHERN NEW YORK RESULTING IN A SLIGHTLY COOLER
DAY ACROSS THOSE AREAS. HIGH PRESSURE WILL BUILD ACROSS THE AREA
AT THE SURFACE AND ALOFT LATER WEDNESDAY THROUGH THURSDAY NIGHT
BRINGING DRY WEATHER ALONG WITH A RETURN TO WELL ABOVE NORMAL
TEMPERATURES BY THURSDAY AFTERNOON. WARM AND SLIGHTLY MORE HUMID
WEATHER CAN BE EXPECTED FOR FRIDAY WITH JUST A SMALL CHANCE FOR AN
AFTERNOON THUNDERSTORM.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
2 PM UPDATE...
FOLLOWED WPC GUIDANCE WHICH LOOKED GOOD. WARM AND DRY MUCH OF THE
WEEKEND THEN BEST CHANCE OF SHOWERS AND THUNDERSTORMS TUESDAY.
VERY WARM WITH HUMIDITY THIS WEEKEND UNDER A LARGE UPPER LEVEL
RIDGE. A SURFACE BOUNDARY WILL BE JUST OF THE CWA IN SE CANADA
WHICH STAYS THERE ALL OF THE LONG TERM. THE BIGGEST QUESTION IS
WHERE THIS SETS UP AND STAYS. MODELS DIFFER ON THIS. WPC LEANS ON
EURO WHICH KEEPS THE BOUNDARY IN CANADA WHILE THE GFS DROPS IT
INTO PA SUN AND MON. HAVE FOLLOWED WPC AND HAVE CHC POPS FAR NORTH
SAT NGT THEN EVERYONE SUNDAY. A COLD FRONT MOVES THROUGH TUESDAY
WITH THE BEST CHANCE OF THE WEEK.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
130 PM UPDATE...
VFR NOW WITH HIGH CLOUDS. RAIN MOVING EAST FROM THE WRN SRN TIER
WILL MAKE IT TO ELM BGM AND MAYBE ITH THIS EVE. VSBYS AND CIGS
SHOULD DROP TO MVFR LATE TONIGHT BGM/ELM. SYR AND RME WILL STAY
DRY AND VFR. AS THE LARGE WEST TO EAST AREA OF RAIN SINKS SOUTH
AVP WILL HAVE RAIN SHORTLY AFTER MIDNIGHT WHICH WILL CONTINUE TO
MIDDAY. AGAIN AVP SHOULD FALL TO MVFR AROUND 9Z. AS THE RAIN MOVES
SOUTH OUT OF ELM BGM CONDITIONS WILL IMPROVE TO VFR AT ELM AROUND
14Z AND AT BGM AFTER 16Z. AVP SHOULD IMPROVE CLOSE TO 18Z AS RAIN
ENDS.
NW TO N WIND AT 5 KTS SHIFTING TO NE TONIGHT AND EAST WED. TONIGHT
MANY LOCATIONS WILL BE LIGHT AND VARIABLE OR CALM.
.OUTLOOK...
WED AFTN-SAT...MAINLY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MSE
NEAR TERM...MSE
SHORT TERM...MSE
LONG TERM...TAC
AVIATION...TAC
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
1046 AM CDT TUE MAY 5 2015
.UPDATE...
SHOWERS/STORMS CONTINUE TO MOVE ACROSS WESTERN PORTIONS OF THE FA.
THIS ACTIVITY WILL SLOWLY SHIFT E AND NE IN THE AREA... MAYBE
REACHING PARTS OF THE I-35 CORRIDOR BY LATE AFTN. HAVE ADJUSTED
POPS/WX TO SHOW CURRENT TRENDS AND STRETCH HIGHER CHANCE AND
LIKELY POPS JUST A LITTLE FURTHER EAST. CLOUDS ARE EXPECTED TO
STAY PUT/INCREASE ACROSS THE AREA. THIS CLOUD COVER ALONG WITH THE
RAIN WILL SLOW THE WARM UP ACROSS AT LEAST THE WESTERN HALF OF
THE AREA... ESPECIALLY IN WESTERN OK AND WESTERN NORTH TEXAS.
UPDATES OUT SOON.
&&
.PREV DISCUSSION... /ISSUED 624 AM CDT TUE MAY 5 2015/
AVIATION...05/12Z TAF ISSUANCE...
ACTIVE AVIATION FORECAST PERIOD. RA WILL CONTINUE TO SLOWLY SPREAD
INTO WRN OK THROUGH THE MORNING HOURS. RA AND TSRA WILL INCREASE
THROUGH THE AFTN AND SPREAD EASTWARD INTO CENTRAL OKLAHOMA INTO
THE EVENING. TRIED TO KEEP TAFS SIMPLE... WITH PREVAILING RA OR
TSRA WHEN NECESSARY. HEAVY SHOWERS AND THUNDERSTORMS MAY RESULT IN
BRIEF PERIODS OF MVFR TO POTENTIALLY IFR VIS THROUGH THE DAY. AS
CLOUD COVER INCREASES THROUGH THE AFTN AND EVENING... MVFR
CEILINGS WILL SLOWLY DROP TO IFR AT SOME SITES OVERNIGHT. WINDS
WILL REMAIN OUT OF THE S/SE THROUGH THE PERIOD... GUSTY THROUGH
THE MORNING AND AFTERNOON... BETWEEN 20 TO 25KTS.
JTK
PREV DISCUSSION... /ISSUED 340 AM CDT TUE MAY 5 2015/
DISCUSSION...
PRIMARY FORECAST CONCERN THIS MORNING IS FOCUSED ON TODAY THROUGH
WEDNESDAY THUNDERSTORM CHANCES. HOWEVER... THUNDERSTORM CHANCES WILL
CONTINUE NEAR DAILY THROUGH THE WEEKEND.
CURRENTLY... CONVECTION ACROSS WEST TEXAS... ALONG AND EAST OF THE
LLANO ESTACADO... CONTINUES... WITH THE SFC LOW SLOWLY EVOLVING
ACROSS THE BIG BEND OF TEXAS. THROUGH MIDNIGHT... NEARLY 4 TO 5
INCHES OF RAIN HAD FALLEN ACROSS PORTIONS OF WEST TEXAS. EXPECT THE
SFC LOW TO SLOWLY LIFT N/NE ACROSS FAR WEST TEXAS... WITH SHOWERS
AND THUNDERSTORMS CONTINUING TO MOVE NWRD ACROSS THE W TX AND THE
PANHANDLES INTO WRN N TX AND FAR WRN OK THROUGH SUNRISE. MESOSCALE
GUIDANCE IS IN GOOD AGREEMENT... ALTHOUGH THE HRRR MIGHT BE A TAD
BULLISH WITH THE EWRD EXTENT OF PRECIP INTO OK THROUGH MID MORNING.
SHOWERS AND THUNDERSTORMS CHANCES WILL SLOWLY INCREASE ACROSS WRN OK
AND WRN N TX THROUGH THE AFTN. LOCALLY HEAVY RAINFALL MAY BE AN
ISSUE LATER THIS MORNING/THIS AFTN AS BANDING MAY DEVELOP ALONG THE
ERN PANHANDLES/WRN OK... WHERE THE BETTER ISENTROPIC RESPONSE MAY
SET UP ON THE ERN PERIPHERY OF THE H500 LOW. WITH GOOD MID-LEVEL
ASCENT AND A NARROW BAND OF MUCAPE VALUES OF 600 TO 900 J/KG...
WOULD NOT BE SURPRISED TO SEE SOME LOCALLY HIGHER RAINFALL GREATER
THAN 1 INCH THROUGH THE DAY. THE NAM IS THE MOST AGGRESSIVE WITH
QPF... SO IT WILL BE INTERESTING TO SEE HOW TODAY UNFOLDS.
AS FOR STRONG TO SEVERE STORMS TODAY... THE BEST CHANCE WILL BE LATE
THIS AFTN/EVENING ACROSS FAR W/SWRN OK AND WRN N TX. OF COURSE...
ANY STORM DEVELOPMENT WILL BE HIGHLY DEPENDENT ON WHAT HAPPENS THIS
MORNING AND AFTN. THERE IS SOME CONCERN CLOUD COVER WILL PERSIST
THROUGH THE AFTN HOURS... LIMITING HEATING/INSTABILITY DEVELOPMENT.
FORCING WILL BE AVAILABLE FROM A WEAK DRYLINE AND BROAD SCALE
ASCENT... AS WELL AS ANY LEFT OVER BOUNDARIES FROM EARLIER
CONVECTION. ALTHOUGH INSTABILITY WILL BE PRIMARY QUESTION THIS
AFTN... THERE WILL BE QUITE A BIT OF SHEAR AVAILABLE... 40 TO 55KTS
0-6KM AND IF WE CAN RECOVER... A WINDOW AROUND 21-03Z FOR SOME 1000-
1400 J/KG SKINNY CAPE PROFILES. MUCH OF THE INSTABILITY WILL BE
ELEVATED... AND GIVEN BUFR PROFILES... LARGE HAIL... UP TO GOLF
BALLS... AND SEVERE WINDS WOULD BE THE PRIMARY HAZARDS... WITH THE
TORNADO HAZARD LOW.
FOR WEDNESDAY... CLUSTERS OR A COMPLEX OF THUNDERSTORMS WILL LIKELY
BE ONGOING AND LIFTING EWRD ACROSS CENTRAL OK THROUGH SUNRISE. THIS
ACTIVITY WILL SLOWLY DIMINISH AND EXIT EWRD THROUGH THE DAY AS THE
H500 SHORT WAVE FINALLY EJECTS NWRD INTO THE NRN HIGH PLAINS. ONCE
AGAIN... HOW THIS ACTIVITY EVOLVES THROUGH THE MORNING WILL PLAY THE
LEAD ROLE IN OUR SEVERE WEATHER CHANCES WED AFTN/EVENING. AT THE
MOMENT... IF WE CAN GET CLEARING ACROSS WRN OK IN THE VICINITY OF
THE DRYLINE... MODEST MLCAPE VALUES CAN BE ANTICIPATED... 1000-1500
J/KG. THIS PAIRED WITH GOOD SHEAR ONCE AGAIN... STORMS ON THE
DRYLINE WILL LIKELY DEVELOP RAPIDLY AND BE GOOD HAIL PRODUCERS... UP
TO TENNIS BALL SIZED... AS WELL AS PRODUCING POTENTIALLY DAMAGING
WIND GUSTS. AS FOR TORNADOES... CHANCES LOOK BETTER IN KS... WHERE
SHEAR/LL WINDS WILL BE ENHANCED BY THE MORE FAVORABLE POSITION OF
THE SFC LOW OVER ERN CO/WRN KS. GUIDANCE SUGGESTS OK AND NRN TX
STORMS WILL MOVE OFF THE DRYLINE... BECOMING ELEVATED QUICKLY AFTER
SUNSET. THE CHANCE FOR SEVERE STORMS WILL DIMINISH OVERNIGHT... WITH
SCATTERED THUNDERSTORMS PERSISTING THROUGH THU MORNING.
FOR THURSDAY INTO FRIDAY... PRECIPITATION CHANCES WILL CONTINUE...
ESPECIALLY THU NIGHT INTO FRI... AS A DIFFUSE FRONTAL BOUNDARY
STALLS/LINGERS NEAR THE OK/KS BORDER... EXTENDING FROM THE PANHANDLE
INTO ERN KS. H500 FLOW REMAINS FAIRLY STATIC AS THE SRN PLAINS
REMAINS SANDWICHED BETWEEN A DEEPENING TROUGH IN THE WEST AND A
SHARP POSITIVE RIDGE INTO THE MID-ATLANTIC COAST. WITH THIS FLOW
REGIME AND THE LINGERING WEAK FRONTAL BOUNDARY... COUPLED WITH
CONTINUOUS MOISTURE ADVECTION FROM THE GULF... PERSISTENT AND
POSSIBLY EXCESSIVE RAINFALL LIKELY... ESPECIALLY FRI INTO SAT AM.
THUNDERSTORM CHANCES WILL CONTINUE THROUGH THE WEEKEND AS THE H500
TROUGH FINALLY LIFTS E/NE ACROSS THE CENTRAL ROCKIES. WITH THIS...
THE DRY LINE WILL MAKE ANOTHER PUSH ON SATURDAY... WITH STRONG TO
SEVERE STORMS POSSIBLE ONCE AGAIN. DETAILS REMAIN HAZY GIVEN WHATS
POSSIBLE TO TRANSPIRE BETWEEN NOW AN THEN. AS WITH TODAY AND WED...
THUNDERSTORMS SAT WILL BE DEPENDENT ON HOW THE ATMOSPHERE RECOVERS
FROM THE MORNING CONVECTION.
PRECIP CHANCES WILL DIMINISH MON INTO TUES.
JTK
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 75 63 78 65 / 60 70 40 50
HOBART OK 67 63 80 63 / 80 80 40 50
WICHITA FALLS TX 68 65 82 66 / 90 70 30 50
GAGE OK 67 60 82 62 / 70 80 20 20
PONCA CITY OK 78 65 78 66 / 30 80 50 40
DURANT OK 78 65 78 66 / 50 70 50 40
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
25/03
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
624 AM CDT TUE MAY 5 2015
.AVIATION...05/12Z TAF ISSUANCE...
ACTIVE AVIATION FORECAST PERIOD. RA WILL CONTINUE TO SLOWLY SPREAD
INTO WRN OK THROUGH THE MORNING HOURS. RA AND TSRA WILL INCREASE
THROUGH THE AFTN AND SPREAD EASTWARD INTO CENTRAL OKLAHOMA INTO
THE EVENING. TRIED TO KEEP TAFS SIMPLE... WITH PREVAILING RA OR
TSRA WHEN NECESSARY. HEAVY SHOWERS AND THUNDERSTORMS MAY RESULT IN
BRIEF PERIODS OF MVFR TO POTENTIALLY IFR VIS THROUGH THE DAY. AS
CLOUD COVER INCREASES THROUGH THE AFTN AND EVENING... MVFR
CEILINGS WILL SLOWLY DROP TO IFR AT SOME SITES OVERNIGHT. WINDS
WILL REMAIN OUT OF THE S/SE THROUGH THE PERIOD... GUSTY THROUGH
THE MORNING AND AFTERNOON... BETWEEN 20 TO 25KTS.
JTK
&&
.PREV DISCUSSION... /ISSUED 340 AM CDT TUE MAY 5 2015/
DISCUSSION...
PRIMARY FORECAST CONCERN THIS MORNING IS FOCUSED ON TODAY THROUGH
WEDNESDAY THUNDERSTORM CHANCES. HOWEVER... THUNDERSTORM CHANCES WILL
CONTINUE NEAR DAILY THROUGH THE WEEKEND.
CURRENTLY... CONVECTION ACROSS WEST TEXAS... ALONG AND EAST OF THE
LLANO ESTACADO... CONTINUES... WITH THE SFC LOW SLOWLY EVOLVING
ACROSS THE BIG BEND OF TEXAS. THROUGH MIDNIGHT... NEARLY 4 TO 5
INCHES OF RAIN HAD FALLEN ACROSS PORTIONS OF WEST TEXAS. EXPECT THE
SFC LOW TO SLOWLY LIFT N/NE ACROSS FAR WEST TEXAS... WITH SHOWERS
AND THUNDERSTORMS CONTINUING TO MOVE NWRD ACROSS THE W TX AND THE
PANHANDLES INTO WRN N TX AND FAR WRN OK THROUGH SUNRISE. MESOSCALE
GUIDANCE IS IN GOOD AGREEMENT... ALTHOUGH THE HRRR MIGHT BE A TAD
BULLISH WITH THE EWRD EXTENT OF PRECIP INTO OK THROUGH MID MORNING.
SHOWERS AND THUNDERSTORMS CHANCES WILL SLOWLY INCREASE ACROSS WRN OK
AND WRN N TX THROUGH THE AFTN. LOCALLY HEAVY RAINFALL MAY BE AN
ISSUE LATER THIS MORNING/THIS AFTN AS BANDING MAY DEVELOP ALONG THE
ERN PANHANDLES/WRN OK... WHERE THE BETTER ISENTROPIC RESPONSE MAY
SET UP ON THE ERN PERIPHERY OF THE H500 LOW. WITH GOOD MID-LEVEL
ASCENT AND A NARROW BAND OF MUCAPE VALUES OF 600 TO 900 J/KG...
WOULD NOT BE SURPRISED TO SEE SOME LOCALLY HIGHER RAINFALL GREATER
THAN 1 INCH THROUGH THE DAY. THE NAM IS THE MOST AGGRESSIVE WITH
QPF... SO IT WILL BE INTERESTING TO SEE HOW TODAY UNFOLDS.
AS FOR STRONG TO SEVERE STORMS TODAY... THE BEST CHANCE WILL BE LATE
THIS AFTN/EVENING ACROSS FAR W/SWRN OK AND WRN N TX. OF COURSE...
ANY STORM DEVELOPMENT WILL BE HIGHLY DEPENDENT ON WHAT HAPPENS THIS
MORNING AND AFTN. THERE IS SOME CONCERN CLOUD COVER WILL PERSIST
THROUGH THE AFTN HOURS... LIMITING HEATING/INSTABILITY DEVELOPMENT.
FORCING WILL BE AVAILABLE FROM A WEAK DRYLINE AND BROAD SCALE
ASCENT... AS WELL AS ANY LEFT OVER BOUNDARIES FROM EARLIER
CONVECTION. ALTHOUGH INSTABILITY WILL BE PRIMARY QUESTION THIS
AFTN... THERE WILL BE QUITE A BIT OF SHEAR AVAILABLE... 40 TO 55KTS
0-6KM AND IF WE CAN RECOVER... A WINDOW AROUND 21-03Z FOR SOME 1000-
1400 J/KG SKINNY CAPE PROFILES. MUCH OF THE INSTABILITY WILL BE
ELEVATED... AND GIVEN BUFR PROFILES... LARGE HAIL... UP TO GOLF
BALLS... AND SEVERE WINDS WOULD BE THE PRIMARY HAZARDS... WITH THE
TORNADO HAZARD LOW.
FOR WEDNESDAY... CLUSTERS OR A COMPLEX OF THUNDERSTORMS WILL LIKELY
BE ONGOING AND LIFTING EWRD ACROSS CENTRAL OK THROUGH SUNRISE. THIS
ACTIVITY WILL SLOWLY DIMINISH AND EXIT EWRD THROUGH THE DAY AS THE
H500 SHORT WAVE FINALLY EJECTS NWRD INTO THE NRN HIGH PLAINS. ONCE
AGAIN... HOW THIS ACTIVITY EVOLVES THROUGH THE MORNING WILL PLAY THE
LEAD ROLE IN OUR SEVERE WEATHER CHANCES WED AFTN/EVENING. AT THE
MOMENT... IF WE CAN GET CLEARING ACROSS WRN OK IN THE VICINITY OF
THE DRYLINE... MODEST MLCAPE VALUES CAN BE ANTICIPATED... 1000-1500
J/KG. THIS PAIRED WITH GOOD SHEAR ONCE AGAIN... STORMS ON THE
DRYLINE WILL LIKELY DEVELOP RAPIDLY AND BE GOOD HAIL PRODUCERS... UP
TO TENNIS BALL SIZED... AS WELL AS PRODUCING POTENTIALLY DAMAGING
WIND GUSTS. AS FOR TORNADOES... CHANCES LOOK BETTER IN KS... WHERE
SHEAR/LL WINDS WILL BE ENHANCED BY THE MORE FAVORABLE POSITION OF
THE SFC LOW OVER ERN CO/WRN KS. GUIDANCE SUGGESTS OK AND NRN TX
STORMS WILL MOVE OFF THE DRYLINE... BECOMING ELEVATED QUICKLY AFTER
SUNSET. THE CHANCE FOR SEVERE STORMS WILL DIMINISH OVERNIGHT... WITH
SCATTERED THUNDERSTORMS PERSISTING THROUGH THU MORNING.
FOR THURSDAY INTO FRIDAY... PRECIPITATION CHANCES WILL CONTINUE...
ESPECIALLY THU NIGHT INTO FRI... AS A DIFFUSE FRONTAL BOUNDARY
STALLS/LINGERS NEAR THE OK/KS BORDER... EXTENDING FROM THE PANHANDLE
INTO ERN KS. H500 FLOW REMAINS FAIRLY STATIC AS THE SRN PLAINS
REMAINS SANDWICHED BETWEEN A DEEPENING TROUGH IN THE WEST AND A
SHARP POSITIVE RIDGE INTO THE MID-ATLANTIC COAST. WITH THIS FLOW
REGIME AND THE LINGERING WEAK FRONTAL BOUNDARY... COUPLED WITH
CONTINUOUS MOISTURE ADVECTION FROM THE GULF... PERSISTENT AND
POSSIBLY EXCESSIVE RAINFALL LIKELY... ESPECIALLY FRI INTO SAT AM.
THUNDERSTORM CHANCES WILL CONTINUE THROUGH THE WEEKEND AS THE H500
TROUGH FINALLY LIFTS E/NE ACROSS THE CENTRAL ROCKIES. WITH THIS...
THE DRY LINE WILL MAKE ANOTHER PUSH ON SATURDAY... WITH STRONG TO
SEVERE STORMS POSSIBLE ONCE AGAIN. DETAILS REMAIN HAZY GIVEN WHATS
POSSIBLE TO TRANSPIRE BETWEEN NOW AN THEN. AS WITH TODAY AND WED...
THUNDERSTORMS SAT WILL BE DEPENDENT ON HOW THE ATMOSPHERE RECOVERS
FROM THE MORNING CONVECTION.
PRECIP CHANCES WILL DIMINISH MON INTO TUES.
JTK
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 77 63 78 65 / 40 70 40 50
HOBART OK 72 63 80 63 / 70 80 40 50
WICHITA FALLS TX 76 65 82 66 / 60 70 30 50
GAGE OK 69 60 82 62 / 70 80 20 20
PONCA CITY OK 79 65 78 66 / 10 80 50 40
DURANT OK 78 65 78 66 / 60 70 50 40
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORMAN OK
340 AM CDT TUE MAY 5 2015
.DISCUSSION...
PRIMARY FORECAST CONCERN THIS MORNING IS FOCUSED ON TODAY THROUGH
WEDNESDAY THUNDERSTORM CHANCES. HOWEVER... THUNDERSTORM CHANCES WILL
CONTINUE NEAR DAILY THROUGH THE WEEKEND.
CURRENTLY... CONVECTION ACROSS WEST TEXAS... ALONG AND EAST OF THE
LLANO ESTACADO... CONTINUES... WITH THE SFC LOW SLOWLY EVOLVING
ACROSS THE BIG BEND OF TEXAS. THROUGH MIDNIGHT... NEARLY 4 TO 5
INCHES OF RAIN HAD FALLEN ACROSS PORTIONS OF WEST TEXAS. EXPECT THE
SFC LOW TO SLOWLY LIFT N/NE ACROSS FAR WEST TEXAS... WITH SHOWERS
AND THUNDERSTORMS CONTINUING TO MOVE NWRD ACROSS THE W TX AND THE
PANHANDLES INTO WRN N TX AND FAR WRN OK THROUGH SUNRISE. MESOSCALE
GUIDANCE IS IN GOOD AGREEMENT... ALTHOUGH THE HRRR MIGHT BE A TAD
BULLISH WITH THE EWRD EXTENT OF PRECIP INTO OK THROUGH MID MORNING.
SHOWERS AND THUNDERSTORMS CHANCES WILL SLOWLY INCREASE ACROSS WRN OK
AND WRN N TX THROUGH THE AFTN. LOCALLY HEAVY RAINFALL MAY BE AN
ISSUE LATER THIS MORNING/THIS AFTN AS BANDING MAY DEVELOP ALONG THE
ERN PANHANDLES/WRN OK... WHERE THE BETTER ISENTROPIC RESPONSE MAY
SET UP ON THE ERN PERIPHERY OF THE H500 LOW. WITH GOOD MID-LEVEL
ASCENT AND A NARROW BAND OF MUCAPE VALUES OF 600 TO 900 J/KG...
WOULD NOT BE SURPRISED TO SEE SOME LOCALLY HIGHER RAINFALL GREATER
THAN 1 INCH THROUGH THE DAY. THE NAM IS THE MOST AGGRESSIVE WITH
QPF... SO IT WILL BE INTERESTING TO SEE HOW TODAY UNFOLDS.
AS FOR STRONG TO SEVERE STORMS TODAY... THE BEST CHANCE WILL BE LATE
THIS AFTN/EVENING ACROSS FAR W/SWRN OK AND WRN N TX. OF COURSE...
ANY STORM DEVELOPMENT WILL BE HIGHLY DEPENDENT ON WHAT HAPPENS THIS
MORNING AND AFTN. THERE IS SOME CONCERN CLOUD COVER WILL PERSIST
THROUGH THE AFTN HOURS... LIMITING HEATING/INSTABILITY DEVELOPMENT.
FORCING WILL BE AVAILABLE FROM A WEAK DRYLINE AND BROAD SCALE
ASCENT... AS WELL AS ANY LEFT OVER BOUNDARIES FROM EARLIER
CONVECTION. ALTHOUGH INSTABILITY WILL BE PRIMARY QUESTION THIS
AFTN... THERE WILL BE QUITE A BIT OF SHEAR AVAILABLE... 40 TO 55KTS
0-6KM AND IF WE CAN RECOVER... A WINDOW AROUND 21-03Z FOR SOME 1000-
1400 J/KG SKINNY CAPE PROFILES. MUCH OF THE INSTABILITY WILL BE
ELEVATED... AND GIVEN BUFR PROFILES... LARGE HAIL... UP TO GOLF
BALLS... AND SEVERE WINDS WOULD BE THE PRIMARY HAZARDS... WITH THE
TORNADO HAZARD LOW.
FOR WEDNESDAY... CLUSTERS OR A COMPLEX OF THUNDERSTORMS WILL LIKELY
BE ONGOING AND LIFTING EWRD ACROSS CENTRAL OK THROUGH SUNRISE. THIS
ACTIVITY WILL SLOWLY DIMINISH AND EXIT EWRD THROUGH THE DAY AS THE
H500 SHORT WAVE FINALLY EJECTS NWRD INTO THE NRN HIGH PLAINS. ONCE
AGAIN... HOW THIS ACTIVITY EVOLVES THROUGH THE MORNING WILL PLAY THE
LEAD ROLE IN OUR SEVERE WEATHER CHANCES WED AFTN/EVENING. AT THE
MOMENT... IF WE CAN GET CLEARING ACROSS WRN OK IN THE VICINITY OF
THE DRYLINE... MODEST MLCAPE VALUES CAN BE ANTICIPATED... 1000-1500
J/KG. THIS PAIRED WITH GOOD SHEAR ONCE AGAIN... STORMS ON THE
DRYLINE WILL LIKELY DEVELOP RAPIDLY AND BE GOOD HAIL PRODUCERS... UP
TO TENNIS BALL SIZED... AS WELL AS PRODUCING POTENTIALLY DAMAGING
WIND GUSTS. AS FOR TORNADOES... CHANCES LOOK BETTER IN KS... WHERE
SHEAR/LL WINDS WILL BE ENHANCED BY THE MORE FAVORABLE POSITION OF
THE SFC LOW OVER ERN CO/WRN KS. GUIDANCE SUGGESTS OK AND NRN TX
STORMS WILL MOVE OFF THE DRYLINE... BECOMING ELEVATED QUICKLY AFTER
SUNSET. THE CHANCE FOR SEVERE STORMS WILL DIMINISH OVERNIGHT... WITH
SCATTERED THUNDERSTORMS PERSISTING THROUGH THU MORNING.
FOR THURSDAY INTO FRIDAY... PRECIPITATION CHANCES WILL CONTINUE...
ESPECIALLY THU NIGHT INTO FRI... AS A DIFFUSE FRONTAL BOUNDARY
STALLS/LINGERS NEAR THE OK/KS BORDER... EXTENDING FROM THE PANHANDLE
INTO ERN KS. H500 FLOW REMAINS FAIRLY STATIC AS THE SRN PLAINS
REMAINS SANDWICHED BETWEEN A DEEPENING TROUGH IN THE WEST AND A
SHARP POSITIVE RIDGE INTO THE MID-ATLANTIC COAST. WITH THIS FLOW
REGIME AND THE LINGERING WEAK FRONTAL BOUNDARY... COUPLED WITH
CONTINUOUS MOISTURE ADVECTION FROM THE GULF... PERSISTENT AND
POSSIBLY EXCESSIVE RAINFALL LIKELY... ESPECIALLY FRI INTO SAT AM.
THUNDERSTORM CHANCES WILL CONTINUE THROUGH THE WEEKEND AS THE H500
TROUGH FINALLY LIFTS E/NE ACROSS THE CENTRAL ROCKIES. WITH THIS...
THE DRY LINE WILL MAKE ANOTHER PUSH ON SATURDAY... WITH STRONG TO
SEVERE STORMS POSSIBLE ONCE AGAIN. DETAILS REMAIN HAZY GIVEN WHATS
POSSIBLE TO TRANSPIRE BETWEEN NOW AN THEN. AS WITH TODAY AND WED...
THUNDERSTORMS SAT WILL BE DEPENDENT ON HOW THE ATMOSPHERE RECOVERS
FROM THE MORNING CONVECTION.
PRECIP CHANCES WILL DIMINISH MON INTO TUES.
JTK
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 77 63 78 65 / 40 70 40 50
HOBART OK 72 63 80 63 / 70 80 40 50
WICHITA FALLS TX 76 65 82 66 / 60 70 30 50
GAGE OK 69 60 82 62 / 70 80 20 20
PONCA CITY OK 79 65 78 66 / 10 80 50 40
DURANT OK 78 65 78 66 / 60 70 50 40
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
307 PM CDT TUE MAY 5 2015
.DISCUSSION...
SCATTERED SHOWERS AND A FEW THUNDERSTORMS CONTINUE TO DEVELOP
ACROSS SE TX IN A NARROW CORRIDOR OF DEEPER MOISTURE. AIR MASS IS
NOT QUITE AS WORKED OVER THE W-SW ZONES AND FEEL ACTIVITY WILL
DRIFT TOWARD THE UNMODIFIED AIR FOR THE REST OF THE AFTN AND
EVENING. PRECIP SHOULD END EARLY THIS EVENING AS THE DISTURBANCE
THAT MOVED INTO THE AREA FROM THE EAST MERGES WITH THE UPPER
TROUGH. A RIBBON OF DEEPER MOISTURE WILL PERSIST OVER THE W-SW
ZONES THROUGH WEDNESDAY. CAN`T REALLY FIND A SFC TRIGGER AND UPPER
LEVEL WINDS ARE LESS DIVERGENT TOMORROW BUT WILL MAINTAIN CHANCE
POPS OUT WEST DUE TO THE HIGHER MOISTURE CONTENT. THE HRRR AND THE
RAP ARE AGGRESSIVE IN DEVELOPING A BAND OF SHOWERS OVER THE SW
ZONES LATE TONIGHT IN THE AXIS OF DEEPER MSTR. THE NAM SOUNDINGS
ON WEDNESDAY LOOK FAIRLY POTENT OVER THE WESTERN HALF OF THE CWA
WITH CAPE VALUES ABOVE 3000...LI VALUES ARE -8 AND A WEAK INVERTED
V SIGNATURE. UPPER LEVEL RIDGING OVER THE GULF AMPLIFIES INTO SE
TX THU-SAT WITH A SERIES OF UPPER LEVEL DISTURBANCES PASSING WELL
TO THE WEST OF THE CWA. WESTERN AREAS COULD GET CLIPPED BY A
DISTURBANCE OR TWO BUT FOR THE MOST PART...FEEL SE TX WILL REMAIN
WARM AND HUMID BUT GENERALLY RAIN FREE.
A STRONGER UPPER LEVEL TROUGH WILL PIVOT ACROSS THE SOUTHERN
ROCKIES INTO THE SOUTHERN PLAINS ON MONDAY. THE UPPER RIDGE OVER
THE GULF IS FLATTENED A BIT AND NUDGED TO THE EAST. THIS SHOULD
BRING SOME OF THE ACTIVE WEATHER A BIT FURTHER EAST SUN-TUE. A
WEAK COLD FRONT WILL ALSO APPROACH SE TX ON TUESDAY AND PROBABLY
STALL SOMEWHERE OVER THE AREA BEFORE RETREATING NORTH. LOOKS LIKE
MON/TUE COULD BECOME ACTIVE WITH PERIODS OF SHRA/TSRA. 43
&&
.MARINE...
PRESSURE GRADIENT REMAINS FAIRLY TIGHT WITH SMALL CRAFT
ADVISORY CONDITIONS BEING OBSERVED IN THE BAYS AND SLIGHTLY UNDER
CRITERIA OFFSHORE. HOWEVER...GUIDANCE SUGGESTS SPEEDS WILL
EVENTUALLY BUMP UP TO 20KTS OFFSHORE LATER THIS EVENING SO AM GOING
TO HOIST THE SCA FLAGS FOR ALL COASTAL WATERS OVERNIGHT. MODERATE
ONSHORE FLOW SHOULD PREVAIL THRU THE WEEKEND WITH INTERMITTENT
PERIODS WHEREAS CAUTION FLAGS MIGHT BE REQUIRED.
TIDES ARE CURRENTLY RUNNING 1-1.5 FEET ABOVE NORMAL. THIS ALONG WITH
ELEVATED SEAS AND SURF WILL PRODUCE STRONGER THAN NORMAL RIP
CURRENTS (AS WAS OBSERVED BY GALVESTON BEACH PATROL TODAY) THRU
MIDWEEK. 47
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 69 84 71 84 71 / 30 30 20 30 20
HOUSTON (IAH) 71 84 72 86 72 / 20 20 10 20 10
GALVESTON (GLS) 73 81 74 81 75 / 20 20 10 20 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 3 AM CDT WEDNESDAY FOR THE FOLLOWING
ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT
TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 4 PM CDT THIS
AFTERNOON FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO
THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
HIGH ISLAND TO FREEPORT 20 TO 60 NM.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
106 PM CDT TUE MAY 5 2015
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...SATELLITE IMAGES AND SURFACE OBSERVATIONS INDICATE
MOSTLY MID LEVEL CLOUDS WITH A FEW LOW AND HIGH CLOUDS ACROSS THE
CWA EARLY THIS AFTERNOON. CEILINGS WERE NEAR 2200FT AT KAPY AND
KPIL TO NEAR 6000FT AT KEBG. EXPECT VFR CONDITIONS TO PREVAIL THE
REST OF THE AFTERNOON INTO THE EVENING BEFORE MVFR CEILINGS
DEVELOP TONIGHT AS LOW TO MID LEVEL MOISTURE INCREASES ACROSS THE
RIO GRANDE VALLEY TONIGHT INTO WED MORNING.
&&
.PREV DISCUSSION... /ISSUED 629 AM CDT TUE MAY 5 2015/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...MVFR CIGS DID NOT MATERIALIZE AT BRO AND HRL WITH
THOSE CIGS AFFECTING MFE ATTM. GUSTY WINDS TO BEGIN AROUND 14Z AT
WHICH TIME THOSE CIGS SHOULD BEGIN TO SCATTER TO VFR BY LATE
MORNING. GUSTS TO 30 KNOTS APPEAR POSSIBLE ESPECIALLY AT MFE WHERE
STRONGER LOW LEVEL WINDS RESIDE. WINDS WILL DECREASE AFTER SUNSET
BUT GUSTS WILL CONTINUE TILL AROUND MIDNIGHT. MVFR CIGS WILL BUILD
BACK IN AFTER SUNSET WHICH WILL CONTINUE THROUGH THE REST OF THE
TAF PERIOD.
PREV DISCUSSION... /ISSUED 416 AM CDT TUE MAY 5 2015/
SHORT TERM /NOW THROUGH WEDNESDAY/...UPPER TROF ACROSS THE FOUR
CORNERS REGION WILL OPEN UP AND WEAKEN AS IT HEADS NORTHEASTWARD
INTO COLORADO THEN BECOME ABSORBED IN THE DEEPENING LARGER SCALE
TROUGH ACROSS THE WESTERN CONUS. DIFFLUENCE REMAINS ACROSS THE
AREA BUT BETTER DYNAMICS ASSOCIATED WITH THE UPPER TROF WILL
REMAIN WELL REMOVED FROM THE AREA. 700MB FLOW STRENGTHENS AND
REINFORCES MID LEVEL CAPPING WITH DRY AIR ADVECTING FROM THE
MEXICAN PLATEAU AND OVER SPREADING THE AREA. LEFT SLIGHT CHANCE
POPS THIS MORNING FOR FAR WESTERN SECTIONS BUT BELIEVE CAP WILL
KEEP THE LID ON MOST IF NOT ALL PRECIPITATION TODAY. HRRR AND
NAM12 SUPPORT THIS IDEA. BREEZY CONDITIONS CONTINUE TODAY WITH
DEEPENING LOW PRESSURE ACROSS WEST TEXAS WITH GUSTS APPROACHING 30
MPH. THERE ARE INDICATIONS IN THE MODELS OF THUNDERSTORMS
DEVELOPING ON THE HIGHER TERRAIN THIS EVENING AND MOVE EASTWARD
TOWARDS OUR AREA BUT DRY AIR SHOULD WEAKEN THEM BEFORE MAKING
ACROSS THE RIVER. THEREFORE WILL KEEP FORECAST DRY TONIGHT. BREEZY
CONDITIONS CONTINUE WEDNESDAY WITH ANOTHER ROUND OF 700MB DRY AIR
ADVECTING FROM THE WEST. CONDITIONS WILL BE FAIRLY SIMILAR TO THE
PAST SEVERAL DAYS. HIGHS IN THE 80S THE NEXT SEVERAL DAYS AND
PERHAPS REACHING 90 DEGREES IN THE FAR NORTHWESTERN SECTIONS OF
ZAPATA COUNTY. LOWS WILL BE IN THE 70S.
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...AS LOW PRESSURE
TROUGHS DEEPEN ACROSS SW U.S. AND JUST OFF THE SE U.S. COAST MID
TO UPPER LEVEL RIDGE BUILDS OVER SOUTH TEXAS AND THE WESTERN
GULF. THIS SHOULD IN A MOSTLY DRY RAINFREE WED NIGHT THROUGH
SUNDAY PERIOD. NOT UNTIL THE WESTERN TROUGH BEGINS TO MOVE
NORTHEAST LATE NEXT WEEKEND INTO EARLY NEXT WEEK WILL THERE BE
SOME INCREASE IN THE CHANCE OF RAIN. MODELS REMAIN RATHER
PERSISTENT IN THIS PATTERN AND HAVE BEEN IN GOOD CONSISTENCY
MAKING FOR A BETTER THAN AVERAGE CONFIDENCE IN THE OUTGOING
FORECAST.
OVERALL, THE EARLY DOG DAYS OF SUMMER WILL BE SETTING UP AS THE
BUILDING UPPER RIDGE AND STRONG CAPPING INVERSION BETWEEN
850-700MB TO DOMINATE. THE BUILDING RIDGE PROMOTES A DIVERGENT Q
VECTOR FIELD OR A CONFLUENT FLOW ALOFT AND THE 850-700MB CAPPING
INVERSION STRENGTHENS WITH A THE PERSISTENT SOUTHWEST FLOW.
WITHOUT ANY LIFTING MECHANISM AND DISTURBANCES/VORT MAXES LIKELY
TO BE DIVERTED NORTHEAST OF THE AREA DO NOT SEE ANY SIGNIFICANT
CHANCE OF RAIN. WITH THAT SAID HAVE KEPT THE LOW CHANCE POPS
ACROSS THE NW ZONES JUST IN CASE A ROUGE THUNDERSTORM MOVES IN
FROM THE SIERRA MADRE.
WARM/HOT, HUMID AND BREEZY WILL BE THE WORD THROUGH AT LEAST
SUNDAY WITH WINDIEST DAYS NEXT WEEKEND AS THE UPPER TROUGH OVER
THE DESERT SW LIFTS INTO THE CENTRAL PLAINS STRENGTHENING THE
PRESSURE GRADIENT. AS WE MOVE INTO NEXT WEEK MODELS SUGGEST AN
INCREASE IN RAIN CHANCES. THE WEAKENING OF THE RIDGE AND A
TRAILING COLD FRONT MOVING INTO CENTRAL TEXAS ALONG WITH POOLING
MOISTURE SOUTH OF THE BOUNDARY LOOKS TO THE INGREDIENTS NEEDED TO
GET A FEW STORMS IN OUR REGION. HAVE BROAD BRUSHED THE CWA WITH
LOW GRADE POPS NEXT MONDAY AND TUESDAY TO ACCOMMODATE THE MODEL
CONSENSUS.
MARINE...NOW THROUGH WEDNESDAY...MODERATE SOUTHEAST WINDS
AND MODERATE SEAS WILL CONTINUE AS HIGH PRES REMAINS DOMINANT
OVER THE SOUTHEAST U.S. AND THE NORTH GULF...COUNTERBALANCED BY
SOMEWHAT LOWER PRESSURE OVER THE SOUTHERN HIGH PLAINS. WINDS AND
SEAS MAY INCREASE SLIGHTLY AT TIMES...WITH SMALL CRAFT EXERCISE
CAUTION TO LOW END SMALL CRAFT ADVISORY CONDITIONS POSSIBLE.
WEDNESDAY NIGHT THROUGH SUNDAY...A MODERATE TO STRONG PRESSURE
GRADIENT TO PERSIST THIS PERIOD. BROAD HIGH PRESSURE OVER THE
GULF TO INTERACT WITH LOWER PRESSURE OVER NW TEXAS TO PRODUCE
MARGINAL SMALL CRAFT ADVISORY CONDITIONS WEDNESDAY NIGHT THROUGH
FRIDAY. LOW PRESSURE STRENGTHEN OVER THE WEEKEND WITH A POSSIBLE
UPTICK IN WINDS AND SEAS.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
61/67/BIRCHFIELD
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
629 AM CDT TUE MAY 5 2015
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...MVFR CIGS DID NOT MATERIALIZE AT BRO AND HRL WITH
THOSE CIGS AFFECTING MFE ATTM. GUSTY WINDS TO BEGIN AROUND 14Z AT
WHICH TIME THOSE CIGS SHOULD BEGIN TO SCATTER TO VFR BY LATE
MORNING. GUSTS TO 30 KNOTS APPEAR POSSIBLE ESPECIALLY AT MFE WHERE
STRONGER LOW LEVEL WINDS RESIDE. WINDS WILL DECREASE AFTER SUNSET
BUT GUSTS WILL CONTINUE TILL AROUND MIDNIGHT. MVFR CIGS WILL BUILD
BACK IN AFTER SUNSET WHICH WILL CONTINUE THROUGH THE REST OF THE
TAF PERIOD.
&&
.PREV DISCUSSION... /ISSUED 416 AM CDT TUE MAY 5 2015/
SHORT TERM /NOW THROUGH WEDNESDAY/...UPPER TROF ACROSS THE FOUR
CORNERS REGION WILL OPEN UP AND WEAKEN AS IT HEADS NORTHEASTWARD
INTO COLORADO THEN BECOME ABSORBED IN THE DEEPENING LARGER SCALE
TROUGH ACROSS THE WESTERN CONUS. DIFFLUENCE REMAINS ACROSS THE
AREA BUT BETTER DYNAMICS ASSOCIATED WITH THE UPPER TROF WILL
REMAIN WELL REMOVED FROM THE AREA. 700MB FLOW STRENGTHENS AND
REINFORCES MID LEVEL CAPPING WITH DRY AIR ADVECTING FROM THE
MEXICAN PLATEAU AND OVER SPREADING THE AREA. LEFT SLIGHT CHANCE
POPS THIS MORNING FOR FAR WESTERN SECTIONS BUT BELIEVE CAP WILL
KEEP THE LID ON MOST IF NOT ALL PRECIPITATION TODAY. HRRR AND
NAM12 SUPPORT THIS IDEA. BREEZY CONDITIONS CONTINUE TODAY WITH
DEEPENING LOW PRESSURE ACROSS WEST TEXAS WITH GUSTS APPROACHING 30
MPH. THERE ARE INDICATIONS IN THE MODELS OF THUNDERSTORMS
DEVELOPING ON THE HIGHER TERRAIN THIS EVENING AND MOVE EASTWARD
TOWARDS OUR AREA BUT DRY AIR SHOULD WEAKEN THEM BEFORE MAKING
ACROSS THE RIVER. THEREFORE WILL KEEP FORECAST DRY TONIGHT. BREEZY
CONDITIONS CONTINUE WEDNESDAY WITH ANOTHER ROUND OF 700MB DRY AIR
ADVECTING FROM THE WEST. CONDITIONS WILL BE FAIRLY SIMILIAR TO THE
PAST SEVERAL DAYS. HIGHS IN THE 80S THE NEXT SEVERAL DAYS AND
PERHAPS REACHING 90 DEGREES IN THE FAR NORTHWESTERN SECTIONS OF
ZAPATA COUNTY. LOWS WILL BE IN THE 70S.
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...AS LOW PRESSURE
TROUGHS DEEPEN ACROSS SW U.S. AND JUST OFF THE SE U.S. COAST MID
TO UPPER LEVEL RIDGE BUILDS OVER SOUTH TEXAS AND THE WESTERN
GULF. THIS SHOULD IN A MOSTLY DRY RAINFREE WED NIGHT THROUGH
SUNDAY PERIOD. NOT UNTIL THE WESTERN TROUGH BEGINS TO MOVE
NORTHEAST LATE NEXT WEEKEND INTO EARLY NEXT WEEK WILL THERE BE
SOME INCREASE IN THE CHANCE OF RAIN. MODELS REMAIN RATHER
PERSISTENT IN THIS PATTERN AND HAVE BEEN IN GOOD CONSISTENCY
MAKING FOR A BETTER THAN AVERAGE CONFIDENCE IN THE OUTGOING
FORECAST.
OVERALL, THE EARLY DOG DAYS OF SUMMER WILL BE SETTING UP AS THE
BUILDING UPPER RIDGE AND STRONG CAPPING INVERSION BETWEEN
850-700MB TO DOMINATE. THE BUILDING RIDGE PROMOTES A DIVERGENT Q
VECTOR FIELD OR A CONFLUENT FLOW ALOFT AND THE 850-700MB CAPPING
INVERSION STRENGTHENS WITH A THE PERSISTENT SOUTHWEST FLOW.
WITHOUT ANY LIFTING MECHANISM AND DISTURBANCES/VORT MAXES LIKELY
TO BE DIVERTED NORTHEAST OF THE AREA DO NOT SEE ANY SIGNIFICANT
CHANCE OF RAIN. WITH THAT SAID HAVE KEPT THE LOW CHANCE POPS
ACROSS THE NW ZONES JUST IN CASE A ROUGE THUNDERSTORM MOVES IN
FROM THE SIERRA MADRE.
WARM/HOT, HUMID AND BREEZY WILL BE THE WORD THROUGH AT LEAST
SUNDAY WITH WINDIEST DAYS NEXT WEEKEND AS THE UPPER TROUGH OVER
THE DESERT SW LIFTS INTO THE CENTRAL PLAINS STRENGTHENING THE
PRESSURE GRADIENT. AS WE MOVE INTO NEXT WEEK MODELS SUGGEST AN
INCREASE IN RAIN CHANCES. THE WEAKENING OF THE RIDGE AND A
TRAILING COLD FRONT MOVING INTO CENTRAL TEXAS ALONG WITH POOLING
MOISTURE SOUTH OF THE BOUNDARY LOOKS TO THE INGREDIENTS NEEDED TO
GET A FEW STORMS IN OUR REGION. HAVE BROAD BRUSHED THE CWA WITH
LOW GRADE POPS NEXT MONDAY AND TUESDAY TO ACCOMMODATE THE MODEL
CONSENSUS.
MARINE...NOW THROUGH WEDNESDAY...MODERATE SOUTHEAST WINDS
AND MODERATE SEAS WILL CONTINUE AS HIGH PRES REMAINS DOMINANT
OVER THE SOUTHEAST U.S. AND THE NORTH GULF...COUNTERBALANCED BY
SOMEWHAT LOWER PRESSURE OVER THE SOUTHERN HIGH PLAINS. WINDS AND
SEAS MAY INCREASE SLIGHTLY AT TIMES...WITH SMALL CRAFT EXERCISE
CAUTION TO LOW END SMALL CRAFT ADVISORY CONDITIONS POSSIBLE.
WEDNESDAY NIGHT THROUGH SUNDAY...A MODERATE TO STRONG PRESSURE
GRADIENT TO PERSIST THIS PERIOD. BROAD HIGH PRESSURE OVER THE
GULF TO INTERACT WITH LOWER PRESSURE OVER NW TEXAS TO PRODUCE
MARGINAL SMALL CRAFT ADVISORY CONDITIONS WEDNESDAY NIGHT THROUGH
FRIDAY. LOW PRESSURE STRENGTHEN OVER THE WEEKEND WITH A POSSIBLE
UPTICK IN WINDS AND SEAS.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
55
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
416 AM CDT TUE MAY 5 2015
.SHORT TERM /NOW THROUGH WEDNESDAY/...UPPER TROF ACROSS THE FOUR
CORNERS REGION WILL OPEN UP AND WEAKEN AS IT HEADS NORTHEASTWARD
INTO COLORADO THEN BECOME ABSORBED IN THE DEEPENING LARGER SCALE
TROUGH ACROSS THE WESTERN CONUS. DIFFLUENCE REMAINS ACROSS THE
AREA BUT BETTER DYNAMICS ASSOCIATED WITH THE UPPER TROF WILL
REMAIN WELL REMOVED FROM THE AREA. 700MB FLOW STRENGTHENS AND
REINFORCES MID LEVEL CAPPING WITH DRY AIR ADVECTING FROM THE
MEXICAN PLATEAU AND OVER SPREADING THE AREA. LEFT SLIGHT CHANCE
POPS THIS MORNING FOR FAR WESTERN SECTIONS BUT BELIEVE CAP WILL
KEEP THE LID ON MOST IF NOT ALL PRECIPITATION TODAY. HRRR AND
NAM12 SUPPORT THIS IDEA. BREEZY CONDITIONS CONTINUE TODAY WITH
DEEPENING LOW PRESSURE ACROSS WEST TEXAS WITH GUSTS APPROACHING 30
MPH. THERE ARE INDICATIONS IN THE MODELS OF THUNDERSTORMS
DEVELOPING ON THE HIGHER TERRAIN THIS EVENING AND MOVE EASTWARD
TOWARDS OUR AREA BUT DRY AIR SHOULD WEAKEN THEM BEFORE MAKING
ACROSS THE RIVER. THEREFORE WILL KEEP FORECAST DRY TONIGHT. BREEZY
CONDITIONS CONTINUE WEDNESDAY WITH ANOTHER ROUND OF 700MB DRY AIR
ADVECTING FROM THE WEST. CONDITIONS WILL BE FAIRLY SIMILIAR TO THE
PAST SEVERAL DAYS. HIGHS IN THE 80S THE NEXT SEVERAL DAYS AND
PERHAPS REACHING 90 DEGREES IN THE FAR NORTHWESTERN SECTIONS OF
ZAPATA COUNTY. LOWS WILL BE IN THE 70S.
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...AS LOW PRESSURE
TROUGHS DEEPEN ACROSS SW U.S. AND JUST OFF THE SE U.S. COAST MID
TO UPPER LEVEL RIDGE BUILDS OVER SOUTH TEXAS AND THE WESTERN
GULF. THIS SHOULD IN A MOSTLY DRY RAINFREE WED NIGHT THROUGH
SUNDAY PERIOD. NOT UNTIL THE WESTERN TROUGH BEGINS TO MOVE
NORTHEAST LATE NEXT WEEKEND INTO EARLY NEXT WEEK WILL THERE BE
SOME INCREASE IN THE CHANCE OF RAIN. MODELS REMAIN RATHER
PERSISTENT IN THIS PATTERN AND HAVE BEEN IN GOOD CONSISTENCY
MAKING FOR A BETTER THAN AVERAGE CONFIDENCE IN THE OUTGOING
FORECAST.
OVERALL, THE EARLY DOG DAYS OF SUMMER WILL BE SETTING UP AS THE
BUILDING UPPER RIDGE AND STRONG CAPPING INVERSION BETWEEN
850-700MB TO DOMINATE. THE BUILDING RIDGE PROMOTES A DIVERGENT Q
VECTOR FIELD OR A CONFLUENT FLOW ALOFT AND THE 850-700MB CAPPING
INVERSION STRENGTHENS WITH A THE PERSISTENT SOUTHWEST FLOW.
WITHOUT ANY LIFTING MECHANISM AND DISTURBANCES/VORT MAXES LIKELY
TO BE DIVERTED NORTHEAST OF THE AREA DO NOT SEE ANY SIGNIFICANT
CHANCE OF RAIN. WITH THAT SAID HAVE KEPT THE LOW CHANCE POPS
ACROSS THE NW ZONES JUST IN CASE A ROUGE THUNDERSTORM MOVES IN
FROM THE SIERRA MADRE.
WARM/HOT, HUMID AND BREEZY WILL BE THE WORD THROUGH AT LEAST
SUNDAY WITH WINDIEST DAYS NEXT WEEKEND AS THE UPPER TROUGH OVER
THE DESERT SW LIFTS INTO THE CENTRAL PLAINS STRENGTHENING THE
PRESSURE GRADIENT. AS WE MOVE INTO NEXT WEEK MODELS SUGGEST AN
INCREASE IN RAIN CHANCES. THE WEAKENING OF THE RIDGE AND A
TRAILING COLD FRONT MOVING INTO CENTRAL TEXAS ALONG WITH POOLING
MOISTURE SOUTH OF THE BOUNDARY LOOKS TO THE INGREDIENTS NEEDED TO
GET A FEW STORMS IN OUR REGION. HAVE BROAD BRUSHED THE CWA WITH
LOW GRADE POPS NEXT MONDAY AND TUESDAY TO ACCOMMODATE THE MODEL
CONSENSUS.
&&
.MARINE...NOW THROUGH WEDNESDAY...MODERATE SOUTHEAST WINDS
AND MODERATE SEAS WILL CONTINUE AS HIGH PRES REMAINS DOMINANT
OVER THE SOUTHEAST U.S. AND THE NORTH GULF...COUNTERBALANCED BY
SOMEWHAT LOWER PRESSURE OVER THE SOUTHERN HIGH PLAINS. WINDS AND
SEAS MAY INCREASE SLIGHTLY AT TIMES...WITH SMALL CRAFT EXERCISE
CAUTION TO LOW END SMALL CRAFT ADVISORY CONDITIONS POSSIBLE.
WEDNESDAY NIGHT THROUGH SUNDAY...A MODERATE TO STRONG PRESSURE
GRADIENT TO PERSIST THIS PERIOD. BROAD HIGH PRESSURE OVER THE
GULF TO INTERACT WITH LOWER PRESSURE OVER NW TEXAS TO PRODUCE
MARGINAL SMALL CRAFT ADVISORY CONDITIONS WEDNESDAY NIGHT THROUGH
FRIDAY. LOW PRESSURE STRENGTHEN OVER THE WEEKEND WITH A POSSIBLE
UPTICK IN WINDS AND SEAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 85 75 83 75 / 10 10 10 10
BROWNSVILLE 86 74 85 75 / 10 10 10 10
HARLINGEN 87 74 87 74 / 10 10 10 10
MCALLEN 89 75 88 75 / 20 10 10 10
RIO GRANDE CITY 87 74 90 74 / 20 10 20 20
SOUTH PADRE ISLAND 81 75 83 75 / 10 10 10 10
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
55/59
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1141 PM CDT Mon May 4 2015
.AVIATION...
/06Z TAFS/
Widespread convection continues across West Central TX and may be
a factor at KABI during the overnight hours. At KABI, VCSH was
included after 08z, with the remaining terminals dry. Low clouds
are expected to develop once again areawide, and may encroach on
IFR range (<1000 ft) during the early morning hours. The most
likely area for IFR ceilings will be along the I-10 corridor.
However, the abundant mid/high cloud cover and strong low-level
jet may preclude ceilings below 1000 ft.
MVFR ceilings will persist most of the day and scattered
convection is anticipated by late morning across much of West
Central TX. Thunderstorms are forecast for the afternoon and
evening hours, but scattered coverage limits the probability at
any given forecast terminal. Thus, -SHRA and VCSH were included as
the prevailing weather group for now.
Johnson
&&
.PREV DISCUSSION... /ISSUED 836 PM CDT Mon May 4 2015/
UPDATE...
Convection continues to the west of the CWA. One batch of storms
is lifting slowly northeast across the South Plains from Lamesa to
near Snyder. A few showers and thunderstorms extend to the south
and southeast from this complex, generally along and north of the
Colorado River. Farther south, a persistent, right-moving
supercell continues to parallel I-10 near Ft. Stockton, with
additional development to its west. Given the proximity of this
storm to Crockett County, a Tornado Watch was issued through 2 AM.
Surface based instability is a bit more limited east of the Pecos
River, so the thinking is that this storm should weaken as it
moves into Crockett County. However, the HRRR has shown a tendency
for additional development in the Big Bend area overnight. There
is also the potential for additional thunderstorms to move into
the Big Country and Concho Valley late tonight and early Tuesday.
If this occurs, it may limit the severe weather potential for
tomorrow afternoon/evening. Will have to wait and see how this
plays out.
PREV DISCUSSION... /ISSUED 629 PM CDT MON MAY 4 2015/
AVIATION...
/00Z TAFS/
Flight conditions will deteriorate at all terminals through the
next 24 hours. Ceilings will drop into the 1500 to 2500 feet
range after 04z at all TAF sites, with southern terminals dropping
to around 800 feet after 08z. Southeast winds gusting over 20
knots are likely area- wide tonight, with these gusts increasing
to near 30 knots tomorrow afternoon across the northern terminals,
and near/over 20 knots farther south. Showers and thunderstorms
may develop at any time during the TAF cycle. For now, have
inserted VCTS at KABI and KSJT for the next couple of hours based
on radar trends..
PREV DISCUSSION... /ISSUED 353 PM CDT Mon May 4 2015/
SHORT TERM...
(Tonight-Tuesday Night)
The main weather concerns for the short term will be the isolated
threat of severe thunderstorms this afternoon and a little more
widespread threat for severe weather Tuesday.
Thunderstorms have already developed this afternoon across much of
west central Texas. So far, storms have been of the single cell
pulse variety and staying below severe levels. We may see an
isolated storm or two produce severe hail this afternoon/evening.
However, the bigger threat for severe weather today will be
farther west over the Permian Basin. We may see a few storms cross
into our western counties this evening...so have kept
precipitation chances going overnight. For tomorrow...an upper
trough over eastern New Mexico will head northeast across west
Texas as the dryline heads east toward our area. Increased cloud
cover may limit instability slightly. However, with decent shear
across the area, expect more organized convection to develop
tomorrow afternoon with a slightly higher threat for severe
weather. Think the best chance for severe storms will be across
the northern and western parts of the area. Storms should continue
into the evening hours.
LONG TERM...
(Wednesday-Monday)
Unsettled weather will continue through the majority of the
extended period, with showers and thunderstorms possible through
next weekend.
The short-wave trough will lift northeast of the area on
Wednesday, while another significant upper trough develops across
the western states. We`ll remain in southwest flow aloft ahead of
this system through Friday, with periodic disturbances moving
across the area. The dryline will remain west of the area on
Wednesday but will mix east into far western counties Thursday
and Friday. Showers and thunderstorms are expected to develop
just about anywhere on Wednesday due to a weaker CAP, with a few
strong to severe storms possible during the late afternoon and
evening hours.
Scattered strong to severe thunderstorms will remain a possibility
Thursday and Friday ahead of the upper trough to our west, with a
continued chance for severe storms next weekend as the upper
trough moves across the Plains.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 62 74 64 80 66 / 30 50 60 40 40
San Angelo 63 76 65 82 66 / 30 30 40 30 30
Junction 64 77 66 80 67 / 20 40 40 40 30
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
25
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
604 AM CDT TUE MAY 5 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 232 AM CDT TUE MAY 5 2015
MAIN FOCUS IS ON RAIN CHANCES AND RESULTANT TEMPERATURES. WEAK
SHORT WAVE TROUGH ENHANCED BY WHAT APPEARS TO BE AN EMBEDDED
MESOSCALE CONVECTIVE VORTICITY WAS SPINNING THROUGH IA OVERNIGHT
RESULTING IN WIDESPREAD SHOWERS AND EMBEDDED THUNDERSTORMS. THUS
FAR THE RAIN HAS BEEN CONFINED TO IA/IL AND EXTREME SOUTHERN WI.
VARIOUS SHORT TERM MODELS SUGGEST SOME OF THE FRONTOGENETIC
FORCING WILL TRY AND SET UP FURTHER NORTH NEAR THE I-90 CORRIDOR
BUT THUS FAR NOTHING HAS BEEN DEVELOPING. NORTHWARD DEVELOPMENT
MAY BE HAMPERED BY ENTRAINMENT OF DRY AIR ON EAST/NORTHEAST WINDS
WHERE LOW LEVEL DEWPOINTS ARE IN THE 30S.
OTHERWISE ANTICIPATE THAT THE RAIN AREA WILL SHIFT EAST AND ANY
LINGERING RAIN CHANCE WILL REALLY DIMINISH AS THE DAY WEARS ON.
WILL MAINTAIN A SLIGHT CHANCE OVER THE SOUTH WHERE BETTER MOISTURE
AND RESIDUAL BOUNDARIES MAY WORK WITH DAYTIME HEATING TO GENERATE
SOME SHOWERS LATER TODAY. ATTENTION THEN SHIFTS TO CONVECTIVE
POTENTIAL TONIGHT AS THE FRONTAL BOUNDARY ACROSS IA MOVES BACK
NORTH. TREND HAS BEEN FOR LESS AND LESS ACTION ALONG THE NORTHWARD
MOVING AND WEAKENING WARM FRONT. STILL...MAINTAINED RAIN RISK LATE
TONIGHT INTO EARLY WEDNESDAY AS MOISTURE CONVERGENCE AND WEAK
FRONTOGENETIC SIGNAL TRANSLATE THROUGH.
CLOUDS AND RAIN SHOULD KEEP TEMPERATURES SOMEWHAT IN CHECK. THIS
ALREADY ACCOUNTED FOR IN PREVIOUS FORECAST SO MINIMAL CHANGES.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 232 AM CDT TUE MAY 5 2015
ACTIVE WEATHER PATTERN ON TAP WITH SEVERAL DISTURBANCES MOVING
THROUGH THE REGION OUT OF THE MEAN LONG WAVE TROUGH OVER THE
WESTERN CONUS. CHALLENGE FOR THE LONGER TERM IS TRYING TO IDENTIFY
THE BEST CHANCE FOR NO RAIN AND HOW TO DEPICT THAT IN THE
FORECAST. SIGNIFICANT SHORT WAVE TROUGH EJECTS NORTHEAST ACROSS
THE PLAINS AND INTO THE DAKOTAS BY THURSDAY...INDUCING A SURFACE
LOW AND TRACKING IT INTO WESTERN ONTARIO BY THURSDAY NIGHT. BEST
RAIN CHANCES WILL REMAIN WEST OF THE GENERAL FORECAST AREA...BUT
THERE IS A SUGGESTION BY SEVERAL OF THE MEDIUM RANGE MODELS THAT
SOME ACTIVITY COULD DEVELOP IN THE WARM/MOIST ADVECTION REGIME OUT
AHEAD OF THE SYSTEM. SO AM FORCED TO KEEP SOME CHANCES IN THE
FORECAST. COLD FRONT TRAILING THIS SYSTEM WILL EDGE THROUGH THE
FORECAST AREA ON FRIDAY AND MAY LINGER AROUND THE AREA INTO
SATURDAY. MODELS SOMEWHAT AT ODDS AS TO HOW FAR SOUTH IT WILL
PUSH...WITH THE GFS MOST AGGRESSIVE WITH THE COOLER AND DRIER AIR.
IF THIS SCENARIO PANS OUT...SATURDAY COULD BE QUITE PLEASANT AND
DRY. ECMWF LESS OPTIMISTIC WITH THE BOUNDARY NEARBY. MESSY
PATTERN THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK AS THE CLOSED
CIRCULATION IN THE BASE OF THE LONG WAVE TROUGH FINALLY EJECTS
NORTHEAST THROUGH THE UPPER MIDWEST. MODELS DIFFER IN THE
DETAILS...AND THERE ARE NOW INDICATIONS THAT THIS GENERAL
CIRCULATION WILL LINGER AROUND THE REGION THROUGH NEARLY ALL OF
NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 604 AM CDT TUE MAY 5 2015
BAND OF SHOWERS NORTH OF THE STATIONARY FRONT CONTINUE TO WORK
SLOWLY NORTH THIS MORNING...BUT THE 05.09Z HRRR SUGGESTS THEY
SHOULD NOT GET MUCH FARTHER NORTH. AS A RESULT...WILL STAY WITH
VCSH AT BOTH TAF SITES FOR NOW BUT WILL MONITOR KLSE CLOSELY FOR
AN UPDATE TO INCLUDE A SHORT PERIOD OF SOME RAIN. MVFR CEILINGS
AHEAD OF THESE SHOWERS ARE ALREADY IMPACTING BOTH TAF SITES AND
WILL INCLUDE THESE INTO THE EARLY AFTERNOON. AFTER THAT...THE
05.06Z NAM WOULD SUGGEST BOTH TAF SITES WOULD BE STUCK IN THE MVFR
CEILINGS ALL DAY WHILE THE 05.09Z RAP FOR THE MOST PART KEEPS VFR.
LOOKING DOWNSTREAM INTO IOWA...THERE IS A BACK EDGE TO THE MVFR
CLOUDS SO WILL GO WITH THE RAP FOR THE REMAINDER OF THE DAY WITH
VFR CONDITIONS. THE FRONT SHOULD THEN START TO LIFT NORTH TOWARD
THE AREA LATE TONIGHT. THE FORCING WITH THE FRONT LOOKS TO BE
RATHER WEAK AND WHILE THERE COULD BE SOME SHOWERS AROUND AFTER
06.06Z...NOT CONFIDENT ENOUGH IN THESE OCCURRING TO EVEN INCLUDE A
VCSH AT THIS TIME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...MW
LONG TERM...MW
AVIATION...04
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1126 AM MDT TUE MAY 5 2015
.UPDATE...VISIBLE SATELLITE IMAGERY AND WYDOT WEBCAMS CONTINUE TO
SHOW AREAS OF DENSE FOG AROUND CHEYENNE TO THE SUMMIT EAST OF
LARAMIE...AND BETWEEN SINCLAIR AND RAWLINS WY. WE UPDATED TO
INCLUDE THE RAWLINS AREA ALONG I-80 IN THE DENSE FOG ADVISORY AND
TO EXTEND THE ADVISORY UNTIL NOON MDT. EXPECT THE FOG WILL START
TO LIFT BY EARLY AFTERNOON. OTHERWISE...NO FURTHER CHANGES NEEDED
IN THE NEAR TERM FORECAST.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 345 AM MDT TUE MAY 5 2015
WEBCAMS ALONG INTERSTATE 80 HAVE CONSISTENTLY SHOWN DENSE FOG FROM
THE SUMMIT TO CHEYENNE OVER THE PAST FEW HOURS. DECIDED TO ADD
CENTRAL LARAMIE COUNTY (CHEYENNE) TO THE DENSE FOG ADVISORY
THRU 16Z WITH THE CYS OBS DROPPING TO ONE QUARTER MILE. THE LOW
CLOUDS AND FOG WILL REMAIN QUITE PERSISTENT THROUGH THE MORNING
WITH THE HRRR MODEL INDICATING LIFR/IFR CONDITIONS THROUGH 18Z
FROM THE INTERSTATE 80 SUMMIT EASTWARD TO CHEYENNE COUNTY. THIS
MAKES SENSE AS THE OVERALL SFC PATTERN OF VERY MOIST SOUTH TO
SOUTHEAST WINDS WILL CONTINUE THROUGH THE MORNING. WATER VAPOR
IMAGERY SHOWS THE SUBTROPICAL UPPER LOW SPINNING OVER NORTHEAST
ARIZONA. THE MODELS MOVE THIS FEATURE TO THE NORTHEAST OVER THE
COURSE OF THE DAY TO NEAR NORTHERN COLORADO BY THIS EVENING.
ONLY AN ISOLATED TO SCATTERED COVERAGE OF SHOWERS IS
EXPECTED THROUGH THE EARLY AFTN ALONG THE COLORADO BORDER.
HOWEVER...MIDLVL HEIGHT FALLS WILL COMBINE WITH INCREASING
DEEP LAYER MOISTURE TO PROMOTE A MORE WIDESPREAD COVERAGE BY THE
LATE AFTN AND EARLY EVENING. MOISTURE IS PLENTIFUL WITH THIS
SYSTEM...IN FACT PW VALUES OF 0.75-1.0 INCHES OVER THE PLAINS ARE 2
STANDARD DEVIATIONS ABOVE NORMAL FOR EARLY MAY. THUS...WITH
RELATIVELY SLOW STORM MOTIONS...LOCALLY HEAVY RAIN WILL BE A
CONCERN ESPECIALLY OVER THE NEBRASKA PANHANDLE. WHILE ISOLATED
TSTMS WILL BE POSSIBLE THIS AFTN...THE VERY WEAK INSTABILITY AND
SHEAR WILL MAKE STRONG STORMS UNLIKELY. SPC HAS DROPPED THE
MARGINAL THREAT OVER THE SOUTHERN PANHANDLE. WITH THE MIDLVL
DISTURBANCE OVERHEAD TONIGHT...WILL KEEP A CHANCE OF SHOWERS
GOING. SOUTHEAST SFC WINDS ARE IN PLACE THRU 12Z WED...SO FOG
WILL AGAIN BE A THREAT OVER PORTIONS OF THE AREA.
THE SHORTWAVE WILL PUSH INTO WESTERN SOUTH DAKOTA/NEBRASKA BY WED
AFTN. THE MODELS SHOW THE HIGHEST QPF OVER THE PLAINS OF SOUTHEAST
WY AS A SFC COLD FRONT INTERACTS WITH GOOD MOISTURE. WILL HAVE
ISOLATED TSTMS DURING THE AFTN WITH SOME LIMITED CAPE. PRECIP
CHANCES DROP OFF WED EVENING BEHIND THE FRONT AS A DRIER AIRMASS
MOVES IN. THERE COULD ACTUALLY BE A 18-24 HR PERIOD FROM WED
EVENING THRU THURS AFTN WHEN MUCH OF THE CWA WILL BE PRECIP FREE.
SCATTERED STORMS WILL ONCE AGAIN DEVELOP ALONG AND WEST OF THE
LARAMIE RANGE BY THURS AFTN...WITH LIMITED COVERAGE OVER THE
PLAINS IN A MORE STABLE AIRMASS.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 345 AM MDT TUE MAY 5 2015
UNSETTLED WEATHER CONTINUES IN THE LONG TERM. MEDIUM RANGE
GUIDANCE CONTINUES TO ADVERTISE THE POSSIBILITY OF WINTER WEATHER
RETURNING TO THE AREA LATE IN THE WEEKEND.
STARTING OFF THURSDAY NIGHT...WE STILL HAVE THE STALLED SURFACE
BOUNDARY LAYING ALONG THE LARAMIE RANGE...OR SLIGHTLY WEST. BOTH
THE GFS AND ECMWF VERY SIMILAR BRINGING ANOTHER PIECE OF ENERGY
NORTHEAST FROM THE DESERT SOUTHWEST TO INTERACT WITH THIS
BOUNDARY...SO WILL KEEP CHANCE POPS GOING FOR THE THURSDAY NIGHT
TIME FRAME. PROBABLY PRETTY LIGHT SHOWERS THOUGH AS HAS BEEN THE
CASE THE PAST FEW NIGHTS. CONVECTION PICKS UP THROUGH FRIDAY AFTERNOON
WITH BOTH MODELS CONCENTRATING ON THE SOUTHERN PANHANDLE AND
NORTHEASTERN COLORADO. SOUTHEAST UPSLOPING WINDS TO CONTINUE.
GFS AND ECMWF CONTINUE TO AGREE ON A CLOSED LOW ROUNDING THE BASE
OF THE LONGWAVE TROUGH SATURDAY MORNING AND BEGINNING TO LIFT
NORTHEAST INTO SOUTHWESTERN COLORADO SATURDAY AFTERNOON. OUR
FORECAST AREA IS SQUARE IN THE WRAP AROUND MOISTURE TO THE NORTH
OF THIS LOW. ECMWF A LITTLE FASTER ON MOVEMENT OVER THE
GFS...MOVING THE LOW INTO CENTRAL NEBRASKA ROUGHLY 12 HOURS FASTER
THAN THE GFS. BOTH ARE COLD THOUGH ON 700MB TEMPERATURES AND COLD
ENOUGH FOR WIDESPREAD SNOW. BOTH ARE SHOWING 850MB WINDS OF 40 TO
45KTS ACROSS THE PANHANDLE AND EASTERN WYOMING. WINTER IS NOT DONE
WITH SOUTHEAST WYOMING AND WE NEED TO BE WATCHING THE EVOLUTION OF
THIS EVENT AS HEAVY SNOW AND WINTER HEADLINES ARE DEFINITELY A
POSSIBILITY FOR PORTIONS OF THE FORECAST AREA...POSSIBLY EVEN THE
PANHANDLE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY MORNING)
ISSUED AT 1126 AM MDT TUE MAY 5 2015
WIDESPREAD IFR/LIFR CEILINGS AND VISIBILITIES TO PERSIST ALONG A
KCYS TO KSNY LINE THROUGH TONIGHT WITH VFR AND SCTD MVFR CIGS
ELSEWHERE TODAY...BECOMING MORE WIDESPREAD MVFR/IFR THIS EVENING.
SCTD SHOWERS SHOULD SPREAD NORTH ACROSS THE AREA TONIGHT.
&&
.FIRE WEATHER...
ISSUED AT 345 AM MDT TUE MAY 5 2015
A COOL AND WET WEATHER PATTERN WILL KEEP FIRE WEATHER CONCERNS VERY
LOW THROUGH THE WEEKEND. AFTERNOON AND EVENING SHOWERS WILL BE
POSSIBLE TODAY THROUGH THURSDAY...WITH GOOD CHANCES FOR MEASURABLE
RAIN. MORE SUBSTANTIAL PRECIPITATION AMOUNTS ARE LOOKING POSSIBLE
BY LATE FRIDAY INTO SUNDAY ASSOCIATED WITH A STRONG STORM SYSTEM.
MINIMUM RELATIVE HUMIDITY VALUES SHOULD BE WELL ABOVE CRITICAL
THRESHOLDS THROUGH THE PERIOD.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...DENSE FOG ADVISORY UNTIL NOON MDT TODAY FOR WYZ116>118.
NE...NONE.
&&
$$
SHORT TERM...ZF
LONG TERM...GCC
AVIATION...RE
FIRE WEATHER...ZF
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
934 AM MDT TUE MAY 5 2015
.UPDATE...VISIBLE SATELLITE IMAGERY AND WYDOT WEBCAMS CONTINUE TO
SHOW AREAS OF DENSE FOG AROUND CHEYENNE TO THE SUMMIT EAST OF
LARAMIE...AND BETWEEN SINCLAIR AND RAWLINS WY. WE UPDATED TO
INCLUDE THE RAWLINS AREA ALONG I-80 IN THE DENSE FOG ADVISORY AND
TO EXTEND THE ADVISORY UNTIL NOON MDT. EXPECT THE FOG WILL START
TO LIFT BY EARLY AFTERNOON. OTHERWISE...NO FURTHER CHANGES NEEDED
IN THE NEAR TERM FORECAST.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 345 AM MDT TUE MAY 5 2015
WEBCAMS ALONG INTERSTATE 80 HAVE CONSISTENTLY SHOWN DENSE FOG FROM
THE SUMMIT TO CHEYENNE OVER THE PAST FEW HOURS. DECIDED TO ADD
CENTRAL LARAMIE COUNTY (CHEYENNE) TO THE DENSE FOG ADVISORY
THRU 16Z WITH THE CYS OBS DROPPING TO ONE QUARTER MILE. THE LOW
CLOUDS AND FOG WILL REMAIN QUITE PERSISTENT THROUGH THE MORNING
WITH THE HRRR MODEL INDICATING LIFR/IFR CONDITIONS THROUGH 18Z
FROM THE INTERSTATE 80 SUMMIT EASTWARD TO CHEYENNE COUNTY. THIS
MAKES SENSE AS THE OVERALL SFC PATTERN OF VERY MOIST SOUTH TO
SOUTHEAST WINDS WILL CONTINUE THROUGH THE MORNING. WATER VAPOR
IMAGERY SHOWS THE SUBTROPICAL UPPER LOW SPINNING OVER NORTHEAST
ARIZONA. THE MODELS MOVE THIS FEATURE TO THE NORTHEAST OVER THE
COURSE OF THE DAY TO NEAR NORTHERN COLORADO BY THIS EVENING.
ONLY AN ISOLATED TO SCATTERED COVERAGE OF SHOWERS IS
EXPECTED THROUGH THE EARLY AFTN ALONG THE COLORADO BORDER.
HOWEVER...MIDLVL HEIGHT FALLS WILL COMBINE WITH INCREASING
DEEP LAYER MOISTURE TO PROMOTE A MORE WIDESPREAD COVERAGE BY THE
LATE AFTN AND EARLY EVENING. MOISTURE IS PLENTIFUL WITH THIS
SYSTEM...IN FACT PW VALUES OF 0.75-1.0 INCHES OVER THE PLAINS ARE 2
STANDARD DEVIATIONS ABOVE NORMAL FOR EARLY MAY. THUS...WITH
RELATIVELY SLOW STORM MOTIONS...LOCALLY HEAVY RAIN WILL BE A
CONCERN ESPECIALLY OVER THE NEBRASKA PANHANDLE. WHILE ISOLATED
TSTMS WILL BE POSSIBLE THIS AFTN...THE VERY WEAK INSTABILITY AND
SHEAR WILL MAKE STRONG STORMS UNLIKELY. SPC HAS DROPPED THE
MARGINAL THREAT OVER THE SOUTHERN PANHANDLE. WITH THE MIDLVL
DISTURBANCE OVERHEAD TONIGHT...WILL KEEP A CHANCE OF SHOWERS
GOING. SOUTHEAST SFC WINDS ARE IN PLACE THRU 12Z WED...SO FOG
WILL AGAIN BE A THREAT OVER PORTIONS OF THE AREA.
THE SHORTWAVE WILL PUSH INTO WESTERN SOUTH DAKOTA/NEBRASKA BY WED
AFTN. THE MODELS SHOW THE HIGHEST QPF OVER THE PLAINS OF SOUTHEAST
WY AS A SFC COLD FRONT INTERACTS WITH GOOD MOISTURE. WILL HAVE
ISOLATED TSTMS DURING THE AFTN WITH SOME LIMITED CAPE. PRECIP
CHANCES DROP OFF WED EVENING BEHIND THE FRONT AS A DRIER AIRMASS
MOVES IN. THERE COULD ACTUALLY BE A 18-24 HR PERIOD FROM WED
EVENING THRU THURS AFTN WHEN MUCH OF THE CWA WILL BE PRECIP FREE.
SCATTERED STORMS WILL ONCE AGAIN DEVELOP ALONG AND WEST OF THE
LARAMIE RANGE BY THURS AFTN...WITH LIMITED COVERAGE OVER THE
PLAINS IN A MORE STABLE AIRMASS.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 345 AM MDT TUE MAY 5 2015
UNSETTLED WEATHER CONTINUES IN THE LONG TERM. MEDIUM RANGE
GUIDANCE CONTINUES TO ADVERTISE THE POSSIBILITY OF WINTER WEATHER
RETURNING TO THE AREA LATE IN THE WEEKEND.
STARTING OFF THURSDAY NIGHT...WE STILL HAVE THE STALLED SURFACE
BOUNDARY LAYING ALONG THE LARAMIE RANGE...OR SLIGHTLY WEST. BOTH
THE GFS AND ECMWF VERY SIMILAR BRINGING ANOTHER PIECE OF ENERGY
NORTHEAST FROM THE DESERT SOUTHWEST TO INTERACT WITH THIS
BOUNDARY...SO WILL KEEP CHANCE POPS GOING FOR THE THURSDAY NIGHT
TIME FRAME. PROBABLY PRETTY LIGHT SHOWERS THOUGH AS HAS BEEN THE
CASE THE PAST FEW NIGHTS. CONVECTION PICKS UP THROUGH FRIDAY AFTERNOON
WITH BOTH MODELS CONCENTRATING ON THE SOUTHERN PANHANDLE AND
NORTHEASTERN COLORADO. SOUTHEAST UPSLOPING WINDS TO CONTINUE.
GFS AND ECMWF CONTINUE TO AGREE ON A CLOSED LOW ROUNDING THE BASE
OF THE LONGWAVE TROUGH SATURDAY MORNING AND BEGINNING TO LIFT
NORTHEAST INTO SOUTHWESTERN COLORADO SATURDAY AFTERNOON. OUR
FORECAST AREA IS SQUARE IN THE WRAP AROUND MOISTURE TO THE NORTH
OF THIS LOW. ECMWF A LITTLE FASTER ON MOVEMENT OVER THE
GFS...MOVING THE LOW INTO CENTRAL NEBRASKA ROUGHLY 12 HOURS FASTER
THAN THE GFS. BOTH ARE COLD THOUGH ON 700MB TEMPERATURES AND COLD
ENOUGH FOR WIDESPREAD SNOW. BOTH ARE SHOWING 850MB WINDS OF 40 TO
45KTS ACROSS THE PANHANDLE AND EASTERN WYOMING. WINTER IS NOT DONE
WITH SOUTHEAST WYOMING AND WE NEED TO BE WATCHING THE EVOLUTION OF
THIS EVENT AS HEAVY SNOW AND WINTER HEADLINES ARE DEFINITELY A
POSSIBILITY FOR PORTIONS OF THE FORECAST AREA...POSSIBLY EVEN THE
PANHANDLE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 536 AM MDT TUE MAY 5 2015
WIDESPREAD IFR/LIFR CEILINGS AND VISIBILITIES TO PERSIST ACROSS
MUCH OF THE AREA THROUGH THE MORNING HOURS. SHOWERS BECOME
WIDESPREAD ACROSS THE SOUTHERN PANHANDLE AND I-80 CORRIDOR LATE
AFTERNOON INTO THE EVENING WITH IFR/LIFR CONDITIONS RETURNING.
&&
.FIRE WEATHER...
ISSUED AT 345 AM MDT TUE MAY 5 2015
A COOL AND WET WEATHER PATTERN WILL KEEP FIRE WEATHER CONCERNS VERY
LOW THROUGH THE WEEKEND. AFTERNOON AND EVENING SHOWERS WILL BE
POSSIBLE TODAY THROUGH THURSDAY...WITH GOOD CHANCES FOR MEASURABLE
RAIN. MORE SUBSTANTIAL PRECIPITATION AMOUNTS ARE LOOKING POSSIBLE
BY LATE FRIDAY INTO SUNDAY ASSOCIATED WITH A STRONG STORM SYSTEM.
MINIMUM RELATIVE HUMIDITY VALUES SHOULD BE WELL ABOVE CRITICAL
THRESHOLDS THROUGH THE PERIOD.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...DENSE FOG ADVISORY UNTIL NOON MDT TODAY FOR WYZ104-105-109-110-
116>118.
NE...NONE.
&&
$$
SHORT TERM...ZF
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...ZF
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
538 AM MDT TUE MAY 5 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 345 AM MDT TUE MAY 5 2015
WEBCAMS ALONG INTERSTATE 80 HAVE CONSISTENTLY SHOWN DENSE FOG FROM
THE SUMMIT TO CHEYENNE OVER THE PAST FEW HOURS. DECIDED TO ADD
CENTRAL LARAMIE COUNTY (CHEYENNE) TO THE DENSE FOG ADVISORY
THRU 16Z WITH THE CYS OBS DROPPING TO ONE QUARTER MILE. THE LOW
CLOUDS AND FOG WILL REMAIN QUITE PERSISTENT THROUGH THE MORNING
WITH THE HRRR MODEL INDICATING LIFR/IFR CONDITIONS THROUGH 18Z
FROM THE INTERSTATE 80 SUMMIT EASTWARD TO CHEYENNE COUNTY. THIS
MAKES SENSE AS THE OVERALL SFC PATTERN OF VERY MOIST SOUTH TO
SOUTHEAST WINDS WILL CONTINUE THROUGH THE MORNING. WATER VAPOR
IMAGERY SHOWS THE SUBTROPICAL UPPER LOW SPINNING OVER NORTHEAST
ARIZONA. THE MODELS MOVE THIS FEATURE TO THE NORTHEAST OVER THE
COURSE OF THE DAY TO NEAR NORTHERN COLORADO BY THIS EVENING.
ONLY AN ISOLATED TO SCATTERED COVERAGE OF SHOWERS IS
EXPECTED THROUGH THE EARLY AFTN ALONG THE COLORADO BORDER.
HOWEVER...MIDLVL HEIGHT FALLS WILL COMBINE WITH INCREASING
DEEP LAYER MOISTURE TO PROMOTE A MORE WIDESPREAD COVERAGE BY THE
LATE AFTN AND EARLY EVENING. MOISTURE IS PLENTIFUL WITH THIS
SYSTEM...IN FACT PW VALUES OF 0.75-1.0 INCHES OVER THE PLAINS ARE 2
STANDARD DEVIATIONS ABOVE NORMAL FOR EARLY MAY. THUS...WITH
RELATIVELY SLOW STORM MOTIONS...LOCALLY HEAVY RAIN WILL BE A
CONCERN ESPECIALLY OVER THE NEBRASKA PANHANDLE. WHILE ISOLATED
TSTMS WILL BE POSSIBLE THIS AFTN...THE VERY WEAK INSTABILITY AND
SHEAR WILL MAKE STRONG STORMS UNLIKELY. SPC HAS DROPPED THE
MARGINAL THREAT OVER THE SOUTHERN PANHANDLE. WITH THE MIDLVL
DISTURBANCE OVERHEAD TONIGHT...WILL KEEP A CHANCE OF SHOWERS
GOING. SOUTHEAST SFC WINDS ARE IN PLACE THRU 12Z WED...SO FOG
WILL AGAIN BE A THREAT OVER PORTIONS OF THE AREA.
THE SHORTWAVE WILL PUSH INTO WESTERN SOUTH DAKOTA/NEBRASKA BY WED
AFTN. THE MODELS SHOW THE HIGHEST QPF OVER THE PLAINS OF SOUTHEAST
WY AS A SFC COLD FRONT INTERACTS WITH GOOD MOISTURE. WILL HAVE
ISOLATED TSTMS DURING THE AFTN WITH SOME LIMITED CAPE. PRECIP
CHANCES DROP OFF WED EVENING BEHIND THE FRONT AS A DRIER AIRMASS
MOVES IN. THERE COULD ACTUALLY BE A 18-24 HR PERIOD FROM WED
EVENING THRU THURS AFTN WHEN MUCH OF THE CWA WILL BE PRECIP FREE.
SCATTERED STORMS WILL ONCE AGAIN DEVELOP ALONG AND WEST OF THE
LARAMIE RANGE BY THURS AFTN...WITH LIMITED COVERAGE OVER THE
PLAINS IN A MORE STABLE AIRMASS.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 345 AM MDT TUE MAY 5 2015
UNSETTLED WEATHER CONTINUES IN THE LONG TERM. MEDIUM RANGE
GUIDANCE CONTINUES TO ADVERTISE THE POSSIBILITY OF WINTER WEATHER
RETURNING TO THE AREA LATE IN THE WEEKEND.
STARTING OFF THURSDAY NIGHT...WE STILL HAVE THE STALLED SURFACE
BOUNDARY LAYING ALONG THE LARAMIE RANGE...OR SLIGHTLY WEST. BOTH
THE GFS AND ECMWF VERY SIMILAR BRINGING ANOTHER PIECE OF ENERGY
NORTHEAST FROM THE DESERT SOUTHWEST TO INTERACT WITH THIS
BOUNDARY...SO WILL KEEP CHANCE POPS GOING FOR THE THURSDAY NIGHT
TIME FRAME. PROBABLY PRETTY LIGHT SHOWERS THOUGH AS HAS BEEN THE
CASE THE PAST FEW NIGHTS. CONVECTION PICKS UP THROUGH FRIDAY AFTERNOON
WITH BOTH MODELS CONCENTRATING ON THE SOUTHERN PANHANDLE AND
NORTHEASTERN COLORADO. SOUTHEAST UPSLOPING WINDS TO CONTINUE.
GFS AND ECMWF CONTINUE TO AGREE ON A CLOSED LOW ROUNDING THE BASE
OF THE LONGWAVE TROUGH SATURDAY MORNING AND BEGINNING TO LIFT
NORTHEAST INTO SOUTHWESTERN COLORADO SATURDAY AFTERNOON. OUR
FORECAST AREA IS SQUARE IN THE WRAP AROUND MOISTURE TO THE NORTH
OF THIS LOW. ECMWF A LITTLE FASTER ON MOVEMENT OVER THE
GFS...MOVING THE LOW INTO CENTRAL NEBRASKA ROUGHLY 12 HOURS FASTER
THAN THE GFS. BOTH ARE COLD THOUGH ON 700MB TEMPERATURES AND COLD
ENOUGH FOR WIDESPREAD SNOW. BOTH ARE SHOWING 850MB WINDS OF 40 TO
45KTS ACROSS THE PANHANDLE AND EASTERN WYOMING. WINTER IS NOT DONE
WITH SOUTHEAST WYOMING AND WE NEED TO BE WATCHING THE EVOLUTION OF
THIS EVENT AS HEAVY SNOW AND WINTER HEADLINES ARE DEFINITELY A
POSSIBILITY FOR PORTIONS OF THE FORECAST AREA...POSSIBLY EVEN THE
PANHANDLE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 536 AM MDT TUE MAY 5 2015
WIDESPREAD IFR/LIFR CEILINGS AND VISIBILITIES TO PERSIST ACROSS
MUCH OF THE AREA THROUGH THE MORNING HOURS. SHOWERS BECOME
WIDESPREAD ACROSS THE SOUTHERN PANHANDLE AND I-80 CORRIDOR LATE
AFTERNOON INTO THE EVENING WITH IFR/LIFR CONDITIONS RETURNING.
&&
.FIRE WEATHER...
ISSUED AT 345 AM MDT TUE MAY 5 2015
A COOL AND WET WEATHER PATTERN WILL KEEP FIRE WEATHER CONCERNS VERY
LOW THROUGH THE WEEKEND. AFTERNOON AND EVENING SHOWERS WILL BE
POSSIBLE TODAY THROUGH THURSDAY...WITH GOOD CHANCES FOR MEASURABLE
RAIN. MORE SUBSTANTIAL PRECIPITATION AMOUNTS ARE LOOKING POSSIBLE
BY LATE FRIDAY INTO SUNDAY ASSOCIATED WITH A STRONG STORM SYSTEM.
MINIMUM RELATIVE HUMIDITY VALUES SHOULD BE WELL ABOVE CRITICAL
THRESHOLDS THROUGH THE PERIOD.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...DENSE FOG ADVISORY UNTIL 10 AM MDT THIS MORNING FOR WYZ116>118.
NE...NONE.
&&
$$
SHORT TERM...ZF
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...ZF
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
348 AM MDT TUE MAY 5 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 345 AM MDT TUE MAY 5 2015
WEBCAMS ALONG INTERSTATE 80 HAVE CONSISTENTLY SHOWN DENSE FOG FROM
THE SUMMIT TO CHEYENNE OVER THE PAST FEW HOURS. DECIDED TO ADD
CENTRAL LARAMIE COUNTY (CHEYENNE) TO THE DENSE FOG ADVISORY
THRU 16Z WITH THE CYS OBS DROPPING TO ONE QUARTER MILE. THE LOW
CLOUDS AND FOG WILL REMAIN QUITE PERSISTENT THROUGH THE MORNING
WITH THE HRRR MODEL INDICATING LIFR/IFR CONDITIONS THROUGH 18Z
FROM THE INTERSTATE 80 SUMMIT EASTWARD TO CHEYENNE COUNTY. THIS
MAKES SENSE AS THE OVERALL SFC PATTERN OF VERY MOIST SOUTH TO
SOUTHEAST WINDS WILL CONTINUE THROUGH THE MORNING. WATER VAPOR
IMAGERY SHOWS THE SUBTROPICAL UPPER LOW SPINNING OVER NORTHEAST
ARIZONA. THE MODELS MOVE THIS FEATURE TO THE NORTHEAST OVER THE
COURSE OF THE DAY TO NEAR NORTHERN COLORADO BY THIS EVENING.
ONLY AN ISOLATED TO SCATTERED COVERAGE OF SHOWERS IS
EXPECTED THROUGH THE EARLY AFTN ALONG THE COLORADO BORDER.
HOWEVER...MIDLVL HEIGHT FALLS WILL COMBINE WITH INCREASING
DEEP LAYER MOISTURE TO PROMOTE A MORE WIDESPREAD COVERAGE BY THE
LATE AFTN AND EARLY EVENING. MOISTURE IS PLENTIFUL WITH THIS
SYSTEM...IN FACT PW VALUES OF 0.75-1.0 INCHES OVER THE PLAINS ARE 2
STANDARD DEVIATIONS ABOVE NORMAL FOR EARLY MAY. THUS...WITH
RELATIVELY SLOW STORM MOTIONS...LOCALLY HEAVY RAIN WILL BE A
CONCERN ESPECIALLY OVER THE NEBRASKA PANHANDLE. WHILE ISOLATED
TSTMS WILL BE POSSIBLE THIS AFTN...THE VERY WEAK INSTABILITY AND
SHEAR WILL MAKE STRONG STORMS UNLIKELY. SPC HAS DROPPED THE
MARGINAL THREAT OVER THE SOUTHERN PANHANDLE. WITH THE MIDLVL
DISTURBANCE OVERHEAD TONIGHT...WILL KEEP A CHANCE OF SHOWERS
GOING. SOUTHEAST SFC WINDS ARE IN PLACE THRU 12Z WED...SO FOG
WILL AGAIN BE A THREAT OVER PORTIONS OF THE AREA.
THE SHORTWAVE WILL PUSH INTO WESTERN SOUTH DAKOTA/NEBRASKA BY WED
AFTN. THE MODELS SHOW THE HIGHEST QPF OVER THE PLAINS OF SOUTHEAST
WY AS A SFC COLD FRONT INTERACTS WITH GOOD MOISTURE. WILL HAVE
ISOLATED TSTMS DURING THE AFTN WITH SOME LIMITED CAPE. PRECIP
CHANCES DROP OFF WED EVENING BEHIND THE FRONT AS A DRIER AIRMASS
MOVES IN. THERE COULD ACTUALLY BE A 18-24 HR PERIOD FROM WED
EVENING THRU THURS AFTN WHEN MUCH OF THE CWA WILL BE PRECIP FREE.
SCATTERED STORMS WILL ONCE AGAIN DEVELOP ALONG AND WEST OF THE
LARAMIE RANGE BY THURS AFTN...WITH LIMITED COVERAGE OVER THE
PLAINS IN A MORE STABLE AIRMASS.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 345 AM MDT TUE MAY 5 2015
UNSETTLED WEATHER CONTINUES IN THE LONG TERM. MEDIUM RANGE
GUIDANCE CONTINUES TO ADVERTISE THE POSSIBILITY OF WINTER WEATHER
RETURNING TO THE AREA LATE IN THE WEEKEND.
STARTING OFF THURSDAY NIGHT...WE STILL HAVE THE STALLED SURFACE
BOUNDARY LAYING ALONG THE LARAMIE RANGE...OR SLIGHTLY WEST. BOTH
THE GFS AND ECMWF VERY SIMILAR BRINGING ANOTHER PIECE OF ENERGY
NORTHEAST FROM THE DESERT SOUTHWEST TO INTERACT WITH THIS
BOUNDARY...SO WILL KEEP CHANCE POPS GOING FOR THE THURSDAY NIGHT
TIME FRAME. PROBABLY PRETTY LIGHT SHOWERS THOUGH AS HAS BEEN THE
CASE THE PAST FEW NIGHTS. CONVECTION PICKS UP THROUGH FRIDAY AFTERNOON
WITH BOTH MODELS CONCENTRATING ON THE SOUTHERN PANHANDLE AND
NORTHEASTERN COLORADO. SOUTHEAST UPSLOPING WINDS TO CONTINUE.
GFS AND ECMWF CONTINUE TO AGREE ON A CLOSED LOW ROUNDING THE BASE
OF THE LONGWAVE TROUGH SATURDAY MORNING AND BEGINNING TO LIFT
NORTHEAST INTO SOUTHWESTERN COLORADO SATURDAY AFTERNOON. OUR
FORECAST AREA IS SQUARE IN THE WRAP AROUND MOISTURE TO THE NORTH
OF THIS LOW. ECMWF A LITTLE FASTER ON MOVEMENT OVER THE
GFS...MOVING THE LOW INTO CENTRAL NEBRASKA ROUGHLY 12 HOURS FASTER
THAN THE GFS. BOTH ARE COLD THOUGH ON 700MB TEMPERATURES AND COLD
ENOUGH FOR WIDESPREAD SNOW. BOTH ARE SHOWING 850MB WINDS OF 40 TO
45KTS ACROSS THE PANHANDLE AND EASTERN WYOMING. WINTER IS NOT DONE
WITH SOUTHEAST WYOMING AND WE NEED TO BE WATCHING THE EVOLUTION OF
THIS EVENT AS HEAVY SNOW AND WINTER HEADLINES ARE DEFINITELY A
POSSIBILITY FOR PORTIONS OF THE FORECAST AREA...POSSIBLY EVEN THE
PANHANDLE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1055 PM MDT MON MAY 4 2015
WIDESPREAD IFR/LIFR FOR THE OVERNIGHT HOURS FOR MOST SOUTHEAST
WYOMING AND NEBRASKA PANHANDLE AIRPORTS WITH SOUTHEAST TO EAST
UPSLOPING WINDS. EXPECT THIS TO LAST THROUGH THE MID TO LATE
MORNING HOURS BEFORE CONDITIONS IMPROVE SOME...BUT THEN WE WILL BE
DEALING WITH SHOWERS AND THUNDERSTORMS. LOW STRATUS RETURNING
TUESDAY EVENING...BECOMING WIDESPREAD ONCE AGAIN.
&&
.FIRE WEATHER...
ISSUED AT 345 AM MDT TUE MAY 5 2015
A COOL AND WET WEATHER PATTERN WILL KEEP FIRE WEATHER CONCERNS VERY
LOW THROUGH THE WEEKEND. AFTERNOON AND EVENING SHOWERS WILL BE
POSSIBLE TODAY THROUGH THURSDAY...WITH GOOD CHANCES FOR MEASURABLE
RAIN. MORE SUBSTANTIAL PRECIPITATION AMOUNTS ARE LOOKING POSSIBLE
BY LATE FRIDAY INTO SUNDAY ASSOCIATED WITH A STRONG STORM SYSTEM.
MINIMUM RELATIVE HUMIDITY VALUES SHOULD BE WELL ABOVE CRITICAL
THRESHOLDS THROUGH THE PERIOD.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...DENSE FOG ADVISORY UNTIL 10 AM MDT THIS MORNING FOR WYZ116>118.
NE...NONE.
&&
$$
SHORT TERM...ZF
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...ZF
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1227 AM MDT THU MAY 7 2015
.UPDATE...
ISSUED AT 1223 AM MDT THU MAY 7 2015
QUICK UPDATE TO GRIDDED POP FIELDS TO INCREASE THE CHANCE OF
PRECIPITATION FOR THE REMAINDER OF THE NIGHT. LATEST HRRR KEEPS
ACTIVITY IN THE REGION THROUGH 5 AM THIS MORNING WITH YET ANOTHER
WAVE LIFTING NORTHEAST ACROSS THE REGION. PRECIP AMOUNTS NOT
EXPECTED TO BE AS HEAVY AS EARLIER TODAY...BUT SOILS ARE SATURATED
IN MANY AREAS...SO WILL KEEP A CLOSE EYE ON CELLS...ESPECIALLY AS
THEY APPROACH POPULATED AREAS.
UPDATE ISSUED AT 940 PM MDT WED MAY 6 2015
HAVE INCREASED THE PRECIPITATION COVERAGE THROUGH TONIGHT AS
THERE CONTINUES TO BE SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS
UPSTREAM. IT APPEARS THAT THERE WILL CONTINUE TO BE WEAK EMBEDDED
DISTURBANCES IN THE SOUTHWEST FLOW OVER THE FORECAST AREA. THIS
WILL BE ENOUGH TO KEEP ISOLATED TO SCATTERED SHOWERS AT TIMES
THROUGHOUT THE NIGHT...GRADUALLY WINDING DOWN TOWARDS MORNING. THE
SOUTHERN PORTION HAS CONTINUED TO BE MORE ACTIVE THAN EXPECTED
WITH ENERGY STREAMING OVER THE FOUR CORNERS AT THIS TIME. THIS
SHOULD PERSIST FOR THE NEXT FEW HOURS. THEREFORE THE FORECAST WILL
SEE THE BIGGEST CHANGES THERE.
&&
.SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT)
ISSUED AT 309 PM MDT WED MAY 6 2015
THE STRONG LOW THAT MOVED OVER THE AREA LAST NIGHT AND THIS
MORNING WILL CONTINUE MOVING INTO THE HIGH PLAINS TONIGHT.
NW AND CENTRAL CO AND NE UT WILL BE BENEATH THE NW FLOW ALOFT
ON THE WEST SIDE OF THE STORM...WHERE UNSTABLE AND MOIST
CONDITIONS WILL CONTINUE TO PRODUCE RAIN SHOWERS AND THUNDERSTORMS
OVER MUCH OF THE AREA. A FEW STORMS HAVE BEEN STRONG ENOUGH TO
PRODUCE SMALL HAIL AND HEAVY RAIN. A WEAK SHORTWAVE TROUGH MOVING
OVER NORTHWEST CO AND NE UT WILL ALSO AS SOME SUPPORT FOR
CONVECTION UNTIL ABOUT 03Z THIS EVENING. SUBSIDENCE AND GRADUALLY
DRIER AIR WILL FILTER INTO EASTER UT...AND NORTHWEST AND CENTRAL
CO AFTER MIDNIGHT. OVER SW CO...THE HRRR AND NAM12 SHOW ANOTHER
WEAK SHORTWAVE WILL BRING INCREASING CLOUDS AND ISOLATED
PRECIPITATION LATE TONIGHT.
THURSDAY MORNING...IN SOUTH FLOW A WEAK WAVE WORKS THROUGH THE
FOUR CORNERS REGION. AVAILABLE MOISTURE WILL BE DIMINISHING THERE
SO ONLY ISOLATED SHOWERS ARE FORECASTED ACROSS THE SOUTH FAVORING
THE SAN JUANS. DEEPER MOISTURE REMAINS ACROSS THE NORTH THURSDAY
ALONG WITH SOME WEAK FRONTAL FORCING. MARGINAL AFTERNOON
INSTABILITY WILL LIMIT THUNDERSTORM COVERAGE MAINLY OVER MTNS
NORTH OF I-70.
THURSDAY NIGHT DRIER SW FLOW INVADES LIMITING NIGHTTIME SHOWERS
TO NEAR THE CONTINENTAL DIVIDE. TEMPERATURES REMAIN NEAR NORMAL.
THE NEXT STRONGER PACIFIC LOW SINKS THROUGH CALIFORNIA ON THURSDAY
THEN BEGINS TO AMBLE INLAND THURSDAY NIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 309 PM MDT WED MAY 6 2015
A HIGHLY AMPLIFIED PROGRESSIVE PATTERN CONTINUES THROUGH THESE
PERIODS. ONE STRONG UPPER LOW WILL PASS ON SATURDAY BRINGING A
BLAST OF NORTHERN AND MOUNTAIN SNOW. TWO OTHER TROUGHS CURRENTLY
ARE TIMED TO PASS MID TO LATE NEXT WEEK.
FRIDAY THE UPPER LOW WITH A MODIFYING BUT IMPRESSIVE -26C COLD
CORE WORKS NORTH OF LAS VEGAS TO SOUTHCENTRAL UTAH FRIDAY NIGHT
AND THROUGH THE FORECAST AREA ON SATURDAY. THE THERMAL RIDGE
BLOSSOMS OVER THE FORECAST AREA FRIDAY AND HAVE RAISED
TEMPERATURES CLOSER TO THE WARMER NAM GUIDANCE. A 70KT JET NOSE
POKES INTO SE UTAH IN THE AFTERNOON AND RAKES THE SOUTH OVERNIGHT.
COOL ADVECTION ALOFT BEGINS TO DESTABILIZE BUT AVAILABLE MOISTURE
IS LIMITED AND MAINLY ACROSS THE NORTH.
SATURDAY THE POTENTIAL VORTICITY CENTER RAKES THE NORTH AS THE
JET WRAPS UP THE FRONT RANGE. FRONTAL FORCING SEEN IN THE PARK
RANGE BY THE AFTERNOON. THE BEST SHOWER COVERAGE WILL BE OVER THE
NORTHERN MOUNTAINS BUT WILL EXTEND INTO THE CENTRAL CO MTNS. SNOW
LEVELS DROP TO AROUND 8KFT...AND WILL BRIEFLY BE LOWER IN
STRONGER CONVECTION. THE LOW LIFTS THROUGH THE NORTHERN PLAINS
SATURDAY NIGHT THROUGH SUNDAY. WRAP- AROUND MOISTURE WILL CONTINUE
TO PRODUCE SHOWERS FAVORING THE NORTH. SUNDAY...SNOW LEVELS LOWER
INTO THE NORTHERN VALLEYS WITH 700MB TEMPS AT -4C THERE.
SIGNIFICANT SNOWFALL IS EXPECTED FOR THIS WEEKEND FOR THE EASTERN
UINTAS AND THE COLORADO MOUNTAINS FROM WYOMING DOWN INTO THE NW
SAN JUANS. TRAVEL THROUGH THESE MOUNTAINS COULD BE HAZARDOUS THIS
WEEKEND. COLDER THAN NORMAL TEMPERATURES EXPECTED ACROSS THE
REGION THROUGH SUNDAY NIGHT. HIGH VALLEY FREEZES ARE POSSIBLE.
MONDAY WARM ADVECTION BEGINS AS A RIDGE BUILDS IN FROM THE WEST.
FLOW ALOFT QUICKLY SWITCHES BACK TO SW AND INCREASES INTO THE NEW
WEEK AS THE NEXT TROUGH WORKS INTO THE PACIFIC NW ON TUESDAY AND
THE GREAT BASIN ON WEDNESDAY. AN ASSOCIATED ZONAL JET FROM CENTRAL
CALIFORNIA INTRUDES INTO THE NORTHERN-CENTRAL FORECAST AREA ON
WEDNESDAY BEGINNING THE CHANCE OF MAINLY RAIN SHOWERS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1145 PM MDT WED MAY 6 2015
SCATTERED -SHRA WITH A FEW -TSRA WILL OCCUR DURING THE OVERNIGHT
HOURS...ESPECIALLY SW AND WEST CENTRAL COLORADO AS A SHORT WAVE
LIFTS ACROSS THIS PORTION TONIGHT. AFTER A MORNING LULL WITH
ISOLATED -SHRA...SCATTERED TSRA WILL DEVELOP ONCE AGAIN WITH THE
PRIMARY FOCUS OVER NW COLORADO AND THE UINTA MOUNTAINS. DIURNAL
STORMS WILL BE LESS NUMEROUS OVER SW COLORADO. SMALL HAIL AND
GUSTY WINDS TO 30KTS WILL BE POSSIBLE WITH THE STRONGEST STORMS.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...JDC
SHORT TERM...CC/JOE
LONG TERM...JOE
AVIATION...PF
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1145 PM MDT WED MAY 6 2015
.UPDATE...
ISSUED AT 940 PM MDT WED MAY 6 2015
HAVE INCREASED THE PRECIPITATION COVERAGE THROUGH TONIGHT AS
THERE CONTINUES TO BE SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS
UPSTREAM. IT APPEARS THAT THERE WILL CONTINUE TO BE WEAK EMBEDDED
DISTURBANCES IN THE SOUTHWEST FLOW OVER THE FORECAST AREA. THIS
WILL BE ENOUGH TO KEEP ISOLATED TO SCATTERED SHOWERS AT TIMES
THROUGHOUT THE NIGHT...GRADUALLY WINDING DOWN TOWARDS MORNING. THE
SOUTHERN PORTION HAS CONTINUED TO BE MORE ACTIVE THAN EXPECTED
WITH ENERGY STREAMING OVER THE FOUR CORNERS AT THIS TIME. THIS
SHOULD PERSIST FOR THE NEXT FEW HOURS. THEREFORE THE FORECAST WILL
SEE THE BIGGEST CHANGES THERE.
&&
.SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT)
ISSUED AT 309 PM MDT WED MAY 6 2015
THE STRONG LOW THAT MOVED OVER THE AREA LAST NIGHT AND THIS
MORNING WILL CONTINUE MOVING INTO THE HIGH PLAINS TONIGHT.
NW AND CENTRAL CO AND NE UT WILL BE BENEATH THE NW FLOW ALOFT
ON THE WEST SIDE OF THE STORM...WHERE UNSTABLE AND MOIST
CONDITIONS WILL CONTINUE TO PRODUCE RAIN SHOWERS AND THUNDERSTORMS
OVER MUCH OF THE AREA. A FEW STORMS HAVE BEEN STRONG ENOUGH TO
PRODUCE SMALL HAIL AND HEAVY RAIN. A WEAK SHORTWAVE TROUGH MOVING
OVER NORTHWEST CO AND NE UT WILL ALSO AS SOME SUPPORT FOR
CONVECTION UNTIL ABOUT 03Z THIS EVENING. SUBSIDENCE AND GRADUALLY
DRIER AIR WILL FILTER INTO EASTER UT...AND NORTHWEST AND CENTRAL
CO AFTER MIDNIGHT. OVER SW CO...THE HRRR AND NAM12 SHOW ANOTHER
WEAK SHORTWAVE WILL BRING INCREASING CLOUDS AND ISOLATED
PRECIPITATION LATE TONIGHT.
THURSDAY MORNING...IN SOUTH FLOW A WEAK WAVE WORKS THROUGH THE
FOUR CORNERS REGION. AVAILABLE MOISTURE WILL BE DIMINISHING THERE
SO ONLY ISOLATED SHOWERS ARE FORECASTED ACROSS THE SOUTH FAVORING
THE SAN JUANS. DEEPER MOISTURE REMAINS ACROSS THE NORTH THURSDAY
ALONG WITH SOME WEAK FRONTAL FORCING. MARGINAL AFTERNOON
INSTABILITY WILL LIMIT THUNDERSTORM COVERAGE MAINLY OVER MTNS
NORTH OF I-70.
THURSDAY NIGHT DRIER SW FLOW INVADES LIMITING NIGHTTIME SHOWERS
TO NEAR THE CONTINENTAL DIVIDE. TEMPERATURES REMAIN NEAR NORMAL.
THE NEXT STRONGER PACIFIC LOW SINKS THROUGH CALIFORNIA ON THURSDAY
THEN BEGINS TO AMBLE INLAND THURSDAY NIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 309 PM MDT WED MAY 6 2015
A HIGHLY AMPLIFIED PROGRESSIVE PATTERN CONTINUES THROUGH THESE
PERIODS. ONE STRONG UPPER LOW WILL PASS ON SATURDAY BRINGING A
BLAST OF NORTHERN AND MOUNTAIN SNOW. TWO OTHER TROUGHS CURRENTLY
ARE TIMED TO PASS MID TO LATE NEXT WEEK.
FRIDAY THE UPPER LOW WITH A MODIFYING BUT IMPRESSIVE -26C COLD
CORE WORKS NORTH OF LAS VEGAS TO SOUTHCENTRAL UTAH FRIDAY NIGHT
AND THROUGH THE FORECAST AREA ON SATURDAY. THE THERMAL RIDGE
BLOSSOMS OVER THE FORECAST AREA FRIDAY AND HAVE RAISED
TEMPERATURES CLOSER TO THE WARMER NAM GUIDANCE. A 70KT JET NOSE
POKES INTO SE UTAH IN THE AFTERNOON AND RAKES THE SOUTH OVERNIGHT.
COOL ADVECTION ALOFT BEGINS TO DESTABILIZE BUT AVAILABLE MOISTURE
IS LIMITED AND MAINLY ACROSS THE NORTH.
SATURDAY THE POTENTIAL VORTICITY CENTER RAKES THE NORTH AS THE
JET WRAPS UP THE FRONT RANGE. FRONTAL FORCING SEEN IN THE PARK
RANGE BY THE AFTERNOON. THE BEST SHOWER COVERAGE WILL BE OVER THE
NORTHERN MOUNTAINS BUT WILL EXTEND INTO THE CENTRAL CO MTNS. SNOW
LEVELS DROP TO AROUND 8KFT...AND WILL BRIEFLY BE LOWER IN
STRONGER CONVECTION. THE LOW LIFTS THROUGH THE NORTHERN PLAINS
SATURDAY NIGHT THROUGH SUNDAY. WRAP- AROUND MOISTURE WILL CONTINUE
TO PRODUCE SHOWERS FAVORING THE NORTH. SUNDAY...SNOW LEVELS LOWER
INTO THE NORTHERN VALLEYS WITH 700MB TEMPS AT -4C THERE.
SIGNIFICANT SNOWFALL IS EXPECTED FOR THIS WEEKEND FOR THE EASTERN
UINTAS AND THE COLORADO MOUNTAINS FROM WYOMING DOWN INTO THE NW
SAN JUANS. TRAVEL THROUGH THESE MOUNTAINS COULD BE HAZARDOUS THIS
WEEKEND. COLDER THAN NORMAL TEMPERATURES EXPECTED ACROSS THE
REGION THROUGH SUNDAY NIGHT. HIGH VALLEY FREEZES ARE POSSIBLE.
MONDAY WARM ADVECTION BEGINS AS A RIDGE BUILDS IN FROM THE WEST.
FLOW ALOFT QUICKLY SWITCHES BACK TO SW AND INCREASES INTO THE NEW
WEEK AS THE NEXT TROUGH WORKS INTO THE PACIFIC NW ON TUESDAY AND
THE GREAT BASIN ON WEDNESDAY. AN ASSOCIATED ZONAL JET FROM CENTRAL
CALIFORNIA INTRUDES INTO THE NORTHERN-CENTRAL FORECAST AREA ON
WEDNESDAY BEGINNING THE CHANCE OF MAINLY RAIN SHOWERS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1145 PM MDT WED MAY 6 2015
SCATTERED -SHRA WITH A FEW -TSRA WILL OCCUR DURING THE OVERNIGHT
HOURS...ESPECIALLY SW AND WEST CENTRAL COLORADO AS A SHORT WAVE
LIFTS ACROSS THIS PORTION TONIGHT. AFTER A MORNING LULL WITH
ISOLATED -SHRA...SCATTERED TSRA WILL DEVELOP ONCE AGAIN WITH THE
PRIMARY FOCUS OVER NW COLORADO AND THE UINTA MOUNTAINS. DIURNAL
STORMS WILL BE LESS NUMEROUS OVER SW COLORADO. SMALL HAIL AND
GUSTY WINDS TO 30KTS WILL BE POSSIBLE WITH THE STRONGEST STORMS.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...EH
SHORT TERM...CC/JOE
LONG TERM...JOE
AVIATION...PF
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1115 PM MDT WED MAY 6 2015
.UPDATE...
ISSUED AT 915 PM MDT WED MAY 6 2015
INCREASED POPS FOR TONIGHT ACROSS THE CONTDVD WITH EMBEDDED SHORT
WAVE LIFTING OUT OF THE FOUR CORNERS AREA.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 345 PM MDT WED MAY 6 2015
CURRENTLY...UPPER LOW PUSHING SLOWLY INTO WRN NEB THIS
AFTERNOON...WHILE WEAKER SHORT WAVE ENERGY WAS DRIFTING NORTH INTO
SOUTHERN COLORADO FROM NM. WITH LACK OF MUCH BL/SURFACE WLY FLOW AND
MOIST GROUND...DEWPOINTS HAVE HELD IN THE MID TO UPPER 40S ACROSS
THE I-25 CORRIDOR AND IN THE LOWER 50S FARTHER EAST NEAR THE KS
BORDER. MESO-ANALYSIS SUGGESTS MIXED LAYER CAPES OVER 1000 J/K
ACROSS THE PLAINS ALONG THE ARKANSAS RIVER THIS AFTERNOON WHERE
SKIES HAVE CLEARED...WITH VALUES 500-1000 J/K FARTHER WEST OVER THE
MOUNTAINS AND VALLEYS. STRONGEST STORMS SO FAR TODAY HAVE BEEN OVER
EL PASO COUNTY...THOUGH ADDITIONAL CELLS HAVE BEGUN DEVELOPING
SOUTHWARD ALONG AND WEST OF I-25 AS OF 2030Z.
TONIGHT...LATEST HRRR BRINGS CONVECTION OFF THE MOUNTAINS AND ACROSS
THE PLAINS LATE THIS AFTERNOON AND EARLY THIS EVENING AS WEAK NM
SHORTWAVE MOVES NORTH...WITH PERHAPS A LOOSELY ORGANIZED LINE
DEVELOPING 00Z-01Z AS STORMS REACH THE KS BORDER. SHEAR IS FAIRLY
WEAK...SO EXPECT MAINLY BRIEF HEAVY RAIN AND SMALL HAIL WITH CELLS
INTO THE EVENING. NAM/GFS END MOST CONVECTION THIS EVENING...WHILE
HRRR DEVELOPS SOME WEAK SHOWERS OVER THE EASTERN MOUNTAINS AND EL
PASO COUNTY 06Z-07Z. WILL GRADUALLY TAPER OFF POPS DURING THE
EVENING...KEEPING SOME LOW CHANCES AFTER MIDNIGHT MAINLY OVER THE
MOUNTAINS AND NORTH OF THE ARKANSAS RIVER. WEAK COLD FRONT WILL DROP
SOUTH THROUGH THE PLAINS LATE TONIGHT...WITH A GRADUALLY SHIFT TO N-
NE WINDS ALONG AND EAST OF I-25 BY SUNRISE WED. MAY SEE SOME LOWER
CLOUDS BEHIND THE BOUNDARY EARLY WED MORNING...ESPECIALLY NEAR THE
KS BORDER WHERE LOW LEVEL MOISTURE WILL BE DEEPER.
THURSDAY...OLD UPPER TROUGH LIFTS INTO THE NORTHERN HIGH PLAINS
WHILE NEW UPPER LOW TAKING SHAPE ACROSS CENTRAL CALIFORNIA. AS A
RESULT...BROAD SOUTHWEST FLOW WILL GRADUALLY STRENGTHEN ACROSS THE
AREA...WHILE SURFACE COLD FRONT BECOMES STATIONARY ALONG THE NM
EARLY IN THE DAY BEFORE LIFTING NORTHWARD TO SOMEWHERE BETWEEN THE
THE ARKANSAS RIVER AND PALMER DIVIDE BY EVENING. BEST BET FOR STORMS
WILL BE NORTH OF THE BOUNDARY...WHERE LOW LEVEL MOISTURE POOLS AND
CAPES CLIMB TOWARD 1000 J/KG. SEVERE THREAT LOOKS FAIRLY LOW AS 0-
6KM SHEAR STAYS BELOW 40 KTS...THOUGH A COUPLE STRONG STORMS WITH
BRIEF HEAVY RAIN AND SMALL HAIL WILL BE LIKELY. ELSEWHERE...ISOLATED
TO SCATTERED CONVECTION LOOKS POSSIBLE...THOUGH INSTABILITY WILL BE
FAIRLY LOW...LIMITING STORM INTENSITY. MAX TEMPS WILL COOL JUST
SLIGHTLY ACROSS THE PLAINS BEHIND THE FRONT...WITH LITTLE CHANGE
ELSEWHERE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 345 PM MDT WED MAY 6 2015
...ACTIVE PATTERN THROUGH AT LEAST SUNDAY...
.FRIDAY...DISTURBANCE ROTATES AROUND THE UPPER LOW OVER NEVADA AND
WILL MOVE INTO THE REGION FROM THE SOUTHWEST. HIGH PRESSURE OVER
THE NORTHERN HIGH PLAINS WILL MAINTAIN UPSLOPE FLOW OVER THE
REGION. CONCEPTUALLY...THIS PATTERN CAN LEAD TO SEVERE CONVECTIVE
WEATHER ON THE PLAINS. MAIN CHALLENGE WILL BE THE AMOUNT OF
INSTABILITY AND LOW LEVEL MOISTURE. NAM HAS MORE COLD AIR OVER THE
REGION...WITH THE ATMOSPHERE REMAINING STABLE. THE GFS HAS THE
UPSLOPE FURTHER NORTH...AND BUFKIT SOUNDINGS SHOW THE LOW LEVEL
MOISTURE MIXING OUT OVER MUCH OF THE PLAINS...ESPECIALLY SOUTH OF
HIGHWAY 50. SUSPECT THE AMOUNT OF LOW LEVEL MOISTURE WILL BE A
COMPROMISE BETWEEN THE GFS AND NAM. THERE IS THE POTENTIAL FOR A
REGION OF HIGHER CAPE NEAR THE FRONT OVER THE EASTERN PLAINS.
CURRENTLY SPC DAY 3 OUTLOOK HAS SEVERE CONVECTION STAYING EAST OF
COLORADO. THIS IS A GOOD CALL GIVEN THE CURRENT MODEL OUTPUT WHICH
TENDS TO KEEP THE ATMOSPHERE STABLE.
.SATURDAY AND SUNDAY...UPPER LOW MOVES ACROSS COLORADO.
INTERESTING FORECAST FOR BOTH DAYS. ON SATURDAY...THERE WILL BE
NO SHORTAGE OF SHEAR AVAILABLE FOR SEVERE CONVECTIVE WEATHER. NAM
IS FURTHEST SOUTH OF THE UPPER LOW AND IT HAS THE MOST IMPRESSIVE
SHEAR. MAIN CHALLENGE WITH NAM SOLUTION WILL BE THE AMOUNT OF
INSTABILITY AS MODEL SOUNDINGS SHOW A GENERALLY STABLE ATMOSPHERE.
GFS AND EC TEND TO BE FURTHER NORTH...AND ARE PREFERRED. THESE
SOLUTIONS WOULD TEND TO MIX OUT THE LOW LEVEL MOISTURE OVER MUCH
OF THE PLAINS...ESPECIALLY SOUTH OF HIGHWAY 50. CURRENT THINKING
IS THE BEST CHANCES FOR STRONG TO SEVERE CONVECTION WILL BE IN
KIOWA AND EL PASO COUNTIES...BUT WILL HAVE TO WATCH FOR FURTHER
SOUTH SOLUTION. ON SUNDAY AS THE UPPER LOW LIFTS TO THE
NORTHEAST...UNSEASONABLY COLD AIR WILL MOVE SOUTHWARD INTO THE
REGION. EC AND GFS STILL HINT AT THE TROWAL MAKING INTO EL PASO
AND TELLER COUNTIES. IF THE TROWAL REACHES THIS FAR SOUTH...THEN A
PERIOD OF SNOW WITH GUSTY NORTH WINDS WILL OCCUR. LATER IN THE
DAY...THE GFS...AND TO A LESSER EXTENT...THE EC HAVE A SECONDARY
DISTURBANCE MOVING IN FROM THE NORTHWEST. BOTH MODELS HAVE
NORTHEAST UPSLOPE DEVELOP ALONG THE EASTERN MOUNTAINS WITH A
PERIOD OF SNOW...AS SNOW LEVELS AS LOW AS 6000 FEET. GIVEN THIS IS
STILL ON DAY 4...DID NOT HIT THIS SOLUTION HARD IN THE GRIDS.
.MONDAY THROUGH WEDNESDAY...AS THE UPPER LOW MOVES TO THE
NORTHEAST...A SHORTWAVE RIDGE BUILDS INTO THE REGION ON MONDAY. EC
AND GFS HINT AT ANOTHER DISTURBANCE MOVING INTO THE REGION ON
TUESDAY OR WEDNESDAY. MODELS CURRENTLY SUGGEST THE BEST LOW LEVEL
MOISTURE WILL MOVE EAST OF THE REGION...WITH CONVECTION NOT BEING
VERY STRONG. . --PGW--
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1115 PM MDT WED MAY 6 2015
MAINLY VFR CONDITIONS EXPECTED AT COS AND PUB OVER THE NEXT 24
HOURS. OUTFLOW FROM EVENING STORMS ACROSS NORTHEASTERN COLORADO
WILL SEND A WEAK BOUNDARY ACROSS THE FAR SE PLAINS THROUGH THE
OVERNIGHT HOURS. GENERALLY WEAK NORTHERLY WINDS OVERNIGHT BECOME
WEAK UPSLOPE EARLY THURSDAY MORNING WITH MVFR AND LOCAL IFR CIGS
POSSIBLE NEAR THE HIGHER TERRAIN WEST OF COS AND PUB. SCATTERED
SHOWERS AND THUNDERSTORMS DEVELOP ACROSS THE HIGHER TERRAIN AFT
18Z WITH THE BEST CHANCES OF STORMS AFFECTING THE TERMINALS BEING
AT COS. BRIEF MVFR CONDITIONS IN HEAVY RAIN...GUSTY WINDS AND
SMALL HAIL WILL BE POSSIBLE IF THE STORMS MOVE ACROSS THE TERMAINALS.
VFR CONDITIONS EXPECTED AT ALS OVER THE NEXT 24 HOURS...WITH STORM
POSSIBLE OVER AND NEAR THE HIGHER TERRAIN WEST AND EAST OF THE AREA.
BREEZY SOUTHERLY WINDS EXPECTED IN THE AFTERNOON.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MW
SHORT TERM...PETERSEN
LONG TERM...PGW
AVIATION...MW
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
400 AM EDT THU MAY 7 2015
.DISCUSSION...
TODAY...SHORT RANGE MODELS IN GOOD AGREEMENT MOVING SFC LOW PRESSURE
AREA NORTHWARD OFFSHORE FROM THE SC COAST NEAR 32N/77W THIS
AFTERNOON. LOW LVL FLOW WILL BE FROM THE NW WITH A DRY SLOT ACROSS
NRN SECTIONS AS PRECIPITABLE WATER VALUES DROP BELOW AN INCH FOR
VOLUSIA COUNTY AND THE NRN INTERIOR. SHOULD SEE MOSTLY SUNNY SKIES
AND WARM TEMPERATURES IN THE MID TO UPPER 80S...EXCEPT SLIGHTLY
COOLER ALONG THE IMMEDIATE COAST AND BEACHES WITH A MID TO LATE
AFTERNOON SEA BREEZE DEVELOPING. GFS/NAM AND HIGH RESOLUTION MODELS
HINTING AT SOME LATE DAY CONVECTION THAT MAY TRY TO GET GOING AND
SNEAK INTO MARTIN COUNTY IN THE EVENING. WILL LEAVE FORECAST POPS
BELOW 15 PERCENT ACROSS FAR SRN SECTIONS FOR NOW. AT THE
BEACHES...OCEAN SWELLS FROM THE LOW PRESSURE OFFSHORE WILL PRODUCE A
MODERATE RISK FOR RIP CURRENTS. SOME ROUGH SURF IS EXPECTED FOR THE
NRN BREVARD AND VOLUSIA COUNTY BEACHES.
TONIGHT...DRY NW FLOW WILL CONTINUE TONIGHT WITH MOSTLY CLEAR SKIES
EXPECTED. DEPENDING ON EXTENT OF SE FL LATE DAY CONVECTION MAY NEED
A LOW POP FOR MARTIN COUNTY IN THE EVENING BUT HAVE LEFT FORECAST
DRY. LOWS MAINLY IN LOWER TO MID 60S...THOUGH COULD SEE SOME UPPER
50S ACROSS NW PORTIONS OF VOLUSIA COUNTY.
FRI-SAT... BROAD SFC LOW CENTERED OFF THE CAROLINA COAST JUST N OF
THE 30TH PARALLEL WILL PLAY AN INDIRECT ROLE IN THE LCL WX PATTERN
THRU THE END OF THE WEEK. AN H100-H70 RIDGE AXIS OVER THE MID ATLC
WILL COMBINE WITH THE LOW TO FORM A TEXTBOOK "REX" TYPE BLOCKING
PATTERN THAT WILL KEEP THE LOW NEARLY STATIONARY. THIS WILL PLACE
CENTRAL FL ON THE DESCENDING LEFT FLANK OF THE LOW...AN AREA USUALLY
ASSOCD WITH DRY AIR ADVECTION DUE TO NWRLY CONTINENTAL FLOW.
THE DEEP SOUTH WILL BE THE PRIMARY SOURCE REGION FOR CENTRAL FL WX.
RAP ANALYSIS CONTINUES TO SHOW A DRY/STABLE AIRMASS OVER GA/AL WITH
H100-H70 MEAN RH VALUES AOB 50PCT...H85-H50 VALUES AOB 20PCT...WHILE
THE ATLANTA RAOB HAS MEASURED PWAT VALUES BLO 0.7" AND A SHARP H85-
H70 SUBSIDENCE INVERSION FOR THREE STRAIGHT SOUNDINGS. EVEN SO...THE
LOW WILL BE POSITIONED CLOSE ENOUGH TO CENTRAL FL TO ALLOW SOME WRAP
AROUND MOISTURE TO WORK ITS WAY INTO THE NRN CWA ON FRI. THE LOW
ALSO WILL PREVENT THE ATLC RIDGE FROM REBUILDING OVER THE
REGION...RESULTING IN A WEAK SFC PGRAD THAT WILL ALLOW BOTH THE EAST
AND WEST COAST SEA BREEZES TO FORM.
THE 00Z MOS GUIDANCE REMAINS ON THE DRY SIDE BUT HAS MANAGED TO
RESOLVE LOW END POPS OVER THE NRN CWA ON FRI...BUT HAS TRENDED DOWN
ON SAT POPS OVER THE PAST 24HRS. DEEP LYR W/NW FLOW WILL PREVAIL
AROUND THE BASE OF THE LOW WHICH WOULD FOCUS ANY SEABREEZE MERGER
OVER THE ERN PENINSULA... IN ADDITION...THE WRLY COMPONENT WILL
GENERATE WARM TEMPS OVER THE INTERIOR WITH AFTN MAXES TOPPING OUT IN
THE U80S/L90S OUTSIDE OF THE IMMEDIATE COAST. THIS MAY BE ENOUGH TO
TRIGGER A FEW SHRAS/TSRAS THRU WEEK`S END... BUT DYNAMIC SUPPORT
WILL BE HARD TO COME BY AS THE FL PENINSULA REMAINS UNDER THE
INFLUENCE OF THE DESCENDING FLANK OF THE STORM. AS SUCH... WILL GO
WITH SLGT CHC POPS N OF U.S. HWY 192 ON FRI...AND N OF SR60 ON SAT.
SUN-WED... THE ATLC RIDGE AXIS WILL REBUILD OVER FL STRAITS AND LIFT
STEADILY NWD THRU EARLY NEXT WEEK AS THE CAROLINA LOW DRIFTS INTO
THE MID ATLC REGION AND BECOMES ABSORBED BY A LARGER SHORT WAVE
FRONTAL TROF. REGIONAL WINDS THRU THE H100-H70 LYR WILL SHIFT TO THE
S/SE AS A RESULT...TAPPING AN AIRMASS THAT IS STRUGGLING TO MAINTAIN
HIGH ENOUGH LOW/MID LVL HUMIDITY TO SUPPORT PRECIP. RAP ANALYSIS
SHOWS H100-H70 RH VALUES REMAIN LARGELY AOB 70PCT...THOUGH A BAND OF
H85-H50 RH AOA 50PCT EXTENDING FROM HONDURAS TO THE CENTRAL BAHAMAS
COULD MAKE UP FOR THE DRIER LOW LVLS.
WILL KEEP PRECIP IN THE FCST THRU THE MIDDLE OF NEXT WEEK...BUT
LIMITING CHANCES TO THE 20-30PCT RANGE AS THE INCREASING INFLUENCE
OF THE ATLC RIDGE WILL TEND TO BLOCK OR CANCEL OUT ANY MID/UPR LVL
DYNAMIC SUPPORT. DVLPG ONSHORE FLOW WILL KEEP TEMPS NEAR OR SLIGHTLY
ABV CLIMO AVG...AFTN MAXES IN THE M/U80S... MRNG MINS IN THE
U60S/L70S.
&&
.AVIATION...VFR.
&&
.MARINE...ADVISORY LEVEL SEAS WILL LINGER ACROSS THE NRN OFFSHORE
WATERS INTO THIS AFTERNOON AND EVENING...AND ACROSS THE SRN OFFSHORE
GULF STREAM WATERS THIS MORNING. WILL CONTINUE THE SCA FOR THE SRN
OFFSHORE LEG INTO MID MORNING AND DROP THE SCA FOR THE CENTRAL
OFFSHORE ZONE THIS AFTN. EXPECT SEAS TO 6-7 TO LINGER ACROSS THE NRN
OFFSHORE LEG AT LEAST INTO THIS EVENING SO HAVE EXTENDED THE SCA
THERE. WINDS UP TO 15-20 KNOTS WILL OCCUR ACROSS THE OFFSHORE
VOLUSIA WATERS TODAY WITH LIGHTER WINDS ACROSS THE SRN LEGS THIS
AFTN AROUND 10 KNOTS.
FRI-FRI NIGHT...STORM SYSTEM STALLED OFF THE CAROLINA COAST WILL
MAINTAIN A GENTLE TO MODERATE SWRLY BREEZE ACRS THE LCL ATLC...BCMG
SE NEAR THE COAST IN THE AFTN AS THE EAST COAST SEA BREEZE DVLPS.
SEAS 2-3FT NEARSHORE AND 3-4FT OFFSHORE.
SAT-MON...AS THE LOW DRIFTS UP THE CAROLINA COAST OVER THE
WEEKEND... THE ATLC RIDGE WILL REBUILD OVER THE FL STRAITS AND WORK
ITS WAY INTO CENTRAL FL BY LATE THIS WEEKEND. A GENTLE TO MODERATE
SWRLY BREEZE ON SAT WILL SHIFT MORE TO THE S/SE ON SUN AS THE RIDGE
BUILDS N. SEAS GENERALLY 2-3FT...UP TO 4FT IN THE GULF STREAM.
&&
.FIRE WEATHER... MIN RHS WILL DROP TO 30-35 PCT ACROSS THE NRN
INTERIOR THIS AFTERNOON WITH NW WINDS TO AROUND 10 MPH. NO HEADLINES
ARE EXPECTED.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 85 62 83 66 / 0 0 20 10
MCO 87 65 88 66 / 0 0 20 0
MLB 85 64 85 65 / 0 0 20 10
VRB 84 62 86 64 / 0 10 20 10
LEE 86 64 86 67 / 0 0 20 0
SFB 87 64 88 67 / 0 0 20 10
ORL 87 66 88 67 / 0 0 20 0
FPR 85 62 86 65 / 0 10 20 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR SEBASTIAN
INLET TO JUPITER INLET 20-60 NM.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR VOLUSIA-
BREVARD COUNTY LINE TO SEBASTIAN INLET 20-60 NM.
SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR FLAGLER
BEACH TO VOLUSIA-BREVARD COUNTY LINE 20-60 NM.
&&
$$
SHORT TERM/AVIATION...VOLKMER
LONG TERM/IMPACT WX....BRAGAW
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
448 AM CDT THU MAY 7 2015
.DISCUSSION...
IR AND RADAR MOSAICS SHOWING A DECAYING MCS ACROSS EASTERN
OKLAHOMA INTO NORTH CENTRAL TEXAS. THE SYSTEM IS DECAYING BECAUSE
LOW LEVEL INFLOW INTO THE SYSTEM IS MUCH WEAKER COMPARED TO A MUCH
STRONGER LOW LEVEL JET JUST TO THE WEST OF THE SYSTEM. THE
TERMINAL FORECAST PACKAGE FOR TODAY/THIS EVENING WILL BE TIED TO A
REMNANT OUTFLOW BOUNDARY PRODUCED BY THIS LARGE CLUSTER OF
THUNDERSTORMS. SHORT TERM PROGS ARE NOT HANDLING THIS SYSTEM VERY
WELL AT ALL...BUT THE HRRR DOES AT LEAST ACKNOWLEDGE THE REMNANT
BOUNDARY WHICH SHOULD SET UP WEST TO EAST ACROSS OUR NORTHERN
ZONES TODAY. THUS...WITH DAYTIME HEATING AND INSTABILITY...THE
BOUNDARY SHOULD SERVE AS A FOCUS FOR SCATTERED CONVECTION WHICH
COULD INFLUENCE AT THE VERY LEAST THE TXK TERMINAL. IF THE
BOUNDARY WAS TO PUSH FURTHER SOUTH TOWARDS THE I-20
CORRIDOR...THEN OUR NE TX TERMINALS WOULD BE IN PLAY FOR AFTERNOON
CONVECTION.
FOR NOW...WILL JUST MAKE MENTION OF VCTS AT THE TXK TERMINAL AND
KEEP ALL OTHER TERMINALS OUT OF THIS MENTION. NOT SAYING OUR OTHER
TERMINALS WILL BE COMPLETELY VOID OF TSRA TODAY BUT CHANCES DO NOT
WARRANT A MENTION ATTM.
MVFR/IFR CEILINGS HAVE BEEN CONFINED TO OUR TYR TERMINAL ONLY AS
OF THIS DISCUSSION EARLY THIS MORNING BUT STILL EXPECTING TO SEE
THIS CLOUD COVER MOVE INTO AT LEAST THE LFK/GGG TERMINALS. THESE
CONDITIONS SHOULD LIFT AND/OR SCATTER OUT BY LATE MORNING/EARLY
AFTERNOON. SHOULD SEE A LITTLE MORE IN THE WAY OF MVFR/IFR
CEILINGS ONCE AGAIN OVERNIGHT TONIGHT INTO EARLY FRIDAY MORNING.
13
&&
.PREV DISCUSSION... /ISSUED 436 AM CDT THU MAY 7 2015/
DISCUSSION...
MCS OVER N TX HAS FINALLY PICKED UP SOME FORWARD MOMENTUM OVER
THE LAST COUPLE OF HRS. LATEST RADAR LOOPS INDICATE PORTIONS OF
THE MCS NORTH OF THE RED RIVER HAVE MORE OF A NELY MOVEMENT AND
ARE BEGINNING TO DISSIPATE...SEGMENT NEAR AND SOUTH OF THE RED
RIVER IS MOVING MORE EASTERLY AND IS A BIT MORE ORGANIZED. IR
IMAGERY OVER THE LAST FEW HRS ALSO INDICATE THAT CLOUD TOPS ARE
WARMING WHICH ALSO SUGGESTS AN OVERALL DECREASE IN INTENSITY.
THESE TRENDS ARE EXPECTED TO CONTINUE AS THE COMPLEX APPROACHES.
THE MCS SHOULD REACH PORTIONS OF SE OK/NE TX NORTH OF I-30 BEFORE
DISSIPATING AND/OR MOVING NE OF THE AREA. MOST OF THE MODELS HAVE
NOT HANDLED THIS COMPLEX PARTICULARLY WELL...ALTHOUGH THE HRRR
SEEMS TO HAVE THE BEST SOLUTION COMPARED TO CURRENT CONDITIONS
AND LATEST TRENDS. INCLUDED UPDATED POP/WX GRIDS FOR THE PERIOD
BEFORE 12Z THIS MORNING.
IN REGARDS TO RAIN CHANCES TODAY...THE MODELS ARE PRACTICALLY
WORTHLESS. NONE OF THEM INITIALIZED PARTICULARLY WELL IN THEIR
HANDLING OF THE ONGOING N TX MCS. THE 00Z NAM AND A COUPLE OF HI-
RES MODELS DEVELOP A COMPLEX ACROSS W TX AND SWEEP IT QUICKLY
EASTWARD WITH QUITE A ROBUST LOOKING MCS FROM TYLER TX TO PRESCOTT
AR AT 00Z THIS EVENING. THE BIGGEST PROBLEM WITH THIS FORECAST IS
THAT IT RESULTS FROM TSTMS SUPPOSEDLY ALREADY ONGOING ACROSS W TX
WHERE NOTHING IS ACTUALLY OCCURRING. THE GFS IS ILL-DEFINED WITH
WIDESPREAD QPF EVERYWHERE AND THE ECMWF APPEARS TO BE SUFFERING
SOME CONVECTIVE FEEDBACK ISSUES.
SINCE THE OVERALL SYNOPTIC PATTERN IS LARGELY UNCHANGED FROM
WEDNESDAY...A PERSISTENCE FORECAST WILL ONCE AGAIN BE USED TODAY
AND FRIDAY. CHANCES FOR CONVECTION MAY BE A BIT HIGHER TODAY IF
THE SEGMENT OF THE ONGOING MCS SOUTH OF THE RED RIVER CAN MAINTAIN
ITSELF LONG ENOUGH TO TAKE ADVANTAGE OF DIURNAL HEATING TODAY.
EVEN IF THE MCS DOES DISSIPATE...A RESIDUAL OUTFLOW BOUNDARY COULD
PROVIDE A FOCUS FOR SHWRS/TSTMS THIS AFTERNOON AND EARLY THIS
EVENING. POTENTIAL WILL EXIST ONCE AGAIN FOR CONVECTION THAT
DEVELOPS FARTHER WEST OVER OK/TX TO MOVE INTO THE ARKLATEX EARLY
FRIDAY MORNING...BUT WILL GENERALLY KEEP POPS LESS THAN 30 PERCENT
AT THIS TIME. AFTERNOON HIGH TEMPERATURES WILL CONTINUE TO RUN IN
THE LOW TO MID 80S AREAWIDE.
SATURDAY WILL LIKELY BE VERY SIMILAR TO TODAY AND FRIDAY.
HOWEVER...A LARGE AND STRONG UPPER TROUGH WILL BE MOVING EWD
THROUGH THE FOUR CORNERS REGION BEFORE EJECTING NEWD INTO KS/NE BY
EARLY SUNDAY MORNING. THE INCREASED LARGE SCALE ASCENT SHOULD ALSO
RESULT IN MUCH HIGHER RAIN CHANCES BEGINNING DURING THE DAY
SATURDAY ACROSS THE NW HALF OF THE CWA.
BEST CHANCES FOR WIDESPREAD...AND POSSIBLY LOCALLY HEAVY
RAINFALL...WILL BE LATE SUNDAY THROUGH MONDAY. A COLD FRONT WILL
BEGIN TO APPROACH AND EVENTUALLY MOVE ACROSS THE AREA AS THE AXIS
OF THE UPPER TROUGH SWINGS EAST ACROSS THE SRN PLAINS. SEVERE
WEATHER WILL BE A POSSIBILITY DURING THIS TIME FRAME...DAMAGING
WINDS AND HAIL SHOULD BE THE PRIMARY THREATS. THE SURFACE FRONT
MAY STALL SOMEWHERE JUST SOUTH OF THE CWA BY TUESDAY. MEDIUM
RANGE MODELS SUGGEST THE 850 MB FRONT WILL STALL SOMEWHERE NEAR
I-20. THIS WILL KEEP SHWRS/TSTMS THROUGH IN THE FORECAST THROUGH
THE EXTENDED PERIODS MAINLY SOUTH OF I-30.
09
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 84 69 85 71 / 30 20 30 30
MLU 86 67 87 70 / 20 10 20 10
DEQ 81 68 82 68 / 30 30 30 40
TXK 83 68 83 69 / 30 20 30 30
ELD 85 68 85 69 / 20 20 20 20
TYR 83 69 84 69 / 30 20 30 30
GGG 84 69 85 70 / 30 20 30 30
LFK 86 70 87 71 / 30 20 30 30
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
09/13
AREA FORECAST DISCUSSION
NWS DULUTH MN
356 AM CDT THU MAY 7 2015
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 355 AM CDT THU MAY 7 2015
AT 345 AM...WE SAW ONE AREA OF SHOWERS EXITING THE INTERNATIONAL
BORDER REGION...WHILE A NEW AREA OF SHOWERS AND POSSIBLE STORMS
WAS MOVING INTO THE SOUTHERN CWA. AN AREA OF PARTIAL CLEARING HAD
DEVELOPED IN BETWEEN THOSE TWO AREAS OF PRECIPITATION.
TEMPERATURES RANGED FROM THE 40S NEAR LAKE SUPERIOR TO THE LOWER
60S IN THE SOUTHERN PORTION OF THE CWA.
THE FOCUS FOR THE PERIOD FROM TODAY THROUGH FRIDAY...AND ESPECIALLY
FOR TODAY...IS TRYING TO RESOLVE THE OVERALL PRECIPITATION POTENTIAL
AND AMOUNTS. AN ANALYSIS OF THE HRRR/RAP/WRF AND THE NAM/GFS/ECMWF
INDICATED NONE OF THE MODELS HAD A GOOD HANDLE ON THE CURRENT
PRECIPITATION AREA...WITH MOST OF THE MODELS TOO SLOW WITH THE
CURRENT SHOWERS MOVING INTO THE SOUTHERN CWA. OVERALL...THINK THE
MODELS DO CATCH UP AND THE TREND FOR INCREASING PRECIPITATION
TODAY SOUNDS LIKE A REASONABLE SCENARIO. WILL GENERALLY HAVE HIGH
POPS ACROSS THE CWA TODAY AND TONIGHT...WITH CHANCES INCREASING
THROUGHOUT THE MORNING TODAY. HIGH RESOLUTION MODELS SUCH AS THE
4KM NMM WRF AND THE HRRR INDICATE THE MODE OF PRECIPITATION SHOULD
BECOME MORE CELLULAR DURING THE DAY. SPC HAS A PORTION OF OUR AREA
IN THE MARGINAL SEVERE WEATHER THREAT AREA...AND THAT SEEMS
REASONABLE GIVEN THE BETTER CHANCE FOR SEEING SOME DAYTIME HEATING
AND PARTIAL SUNSHINE IN THE SOUTHERN PORTION OF THE CWA.
PRECIPITABLE WATER VALUES THIS MORNING ARE GENERALLY IN THE 1.2
INCH RANGE. A FORMIDABLE LLJ OF UP TO 50 KT WAS EVIDENT THROUGHOUT
THE PLAINS AND UPPER MIDWEST.
TODAY...WILL GO WITH FAIRLY HIGH POPS. PRECIPITATION WILL COME IN
WAVES AND INCREASE THROUGHOUT THE DAY. HIGHS SHOULD GENERALLY BE
IN THE 70S...ALTHOUGH SOME 60S ARE POSSIBLE IN SPOTS...WITH 40S
AND 50S NEAR THE LAKE. COULD BE SOME STRONG THUNDERSTORMS DURING
THE LATTER PORTION OF THE DAY...AND POSSIBLY AN ISOLATED SEVERE
THUNDERSTORM ACROSS THE SOUTHEAST HALF OF THE CWA.
TONIGHT...SHOWERS AND THUNDERSTORMS WILL BE LIKELY. A FEW STRONG
STORMS WILL AGAIN BE POSSIBLE DURING THE EVENING...ESPECIALLY
ACROSS THE SOUTHEASTERN PORTION OF THE CWA. BY 06Z FRIDAY...THE
COLD FRONT SHOULD REACH THE DULUTH AREA...AND IT SHOULD JUST ABOUT
CLEAR THE SOUTHEAST CWA BY 12Z FRIDAY. WINDS WILL SWITCH TO THE
NORTHWEST BEHIND THE FRONT.
FRIDAY...THE SHOWERS AND STORMS WILL GRADUALLY DIMINISH FROM THE
WEST. ONLY A FEW SHOWERS WILL LINGER FAR EAST INTO THE AFTERNOON.
DRIER AIR WILL PUSH IN FROM THE NORTHWEST...AS DRIER AND COOLER
AIR SPREADS INTO THE AREA FROM CANADIAN HIGH PRESSURE. HIGHS WILL
BE IN THE 50S FOR MOST OF NE MN...WITH SOME 60S IN WI.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU MAY 7 2015
HIGH PRESSURE AT THE SURFACE WILL BE BUILDING IN ACROSS SRN MANITOBA
AND WRN ONTARIO FRIDAY NIGHT AND SATURDAY...AND INTO LAKE SUPERIOR
SAT NIGHT. AS THE HIGH SHIFTS SLIGHTLY TO THE EAST THE NEXT
SIGNIFICANT LOW PRESSURE SYSTEM WILL MOVE FROM THE SRN PLAINS INTO
THE UPPER MIDWEST BY LATE SUNDAY NIGHT/MON MORNING. THE COMBINATION
OF THE SFC HIGH AND APPROACHING LOW TO THE SOUTH WILL INDUCE A
PERSISTENT E/NE WIND OFF LAKE SUPERIOR FRI NIGHT THROUGH MONDAY
NIGHT. THE APPROACHING SYSTEM WILL ONCE AGAIN DRAW UP A LARGE SUPPLY
OF MOISTURE FROM THE SOUTH AND DEPOSIT IT IN THE FORM OF WIDESPREAD
RAIN SHOWERS ACROSS THE NORTHLAND THROUGH THE DAY SUNDAY AND
CONTINUING INTO MONDAY AS THE SYSTEM WRAPS UP MOVING INTO THE GREAT
LAKES. THIS SYSTEM WILL BE FAIRLY DYNAMIC WITH A STRONG WARM FRONT
OUT AHEAD OF THE LOW...WHICH COULD BE CAPABLE OF PRODUCING SCATTERED
THUNDERSTORMS WITH THE SHOWERS DURING THE DAY SUNDAY. THE SYSTEM
THEN BEGINS TO LOOK MORE LIKE A WINTER-TYPE LOW AS AN AREA OF COLDER
AIR FILLS IN ON THE BACK SIDE...AND A TROWAL-LOOKING FEATURE
DEVELOPS TO THE EAST WITH AN AREA OF ROBUST STRATIFORM RAIN FORMING
IN THE DEFORMATION ZONE ACROSS NRN MN. THE RAIN SHOULD LINGER INTO
LATE MONDAY AND EARLY TUESDAY AS THE COLD AIR CONTINUES TO DROP IN
ACROSS THE UPPER MIDWEST BEHIND THE DEPARTING SYSTEM. THE AMT AND
DEPTH OF THE COLD AIR COULD ACTUALLY CHANGE OVER TO RAIN OR MIX WITH
SNOW AT TIMES TUESDAY MORNING. NO ACCUMULATION IS EXPECTED AT THIS
TIME. HIGH PRESSURE WILL BUILD IN BEHIND THE SYSTEM INTO THE MIDDLE
OF THE WEEK...BUT ONLY FOR A BRIEF PERIOD AS THE NEXT WEAK INVERTED
TROUGH SLIDES IN FROM THE WEST WITH ADDITIONAL CHANCES FOR LIGHT
RAIN.
TEMPERATURES WILL BE NOTICEABLY COOLER THROUGH MUCH OF THE EXTENDED
PERIOD...ESPECIALLY AROUND THE TWIN PORTS AREA WITH A PERSISTENT
E/NE WIND OFF LAKE SUPERIOR. WHILE AREAS INLAND COULD SEE UPPER 50S
AND 60S AT TIMES...LOCATIONS CLOSER TO THE LAKE WILL ONLY SEE 40S
AND LOWER 50S DURING THE DAY. THE PRESENCE OF A LAKE BREEZE WILL
MAKE IT SEEM EVEN COLDER. OVERNIGHT LOWS WILL GENERALLY BOTTOM OUT
IN THE 30S AND LOWER 40S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1245 AM CDT THU MAY 7 2015
MAINLY VFR-MVFR CEILINGS AND VISIBILITIES ACROSS NORTHERN
MINNESOTA AND NORTHWEST WISCONSIN AS OF 05Z. SOME ISOLATED SHOWERS
EXPECTED THE NEXT FEW HOURS...BRINGING MVFR CEILINGS AND
VISIBILITIES. WITH THE MOISTURE CONTINUING TO PUMP UP INTO THE
AREA...EXPECT SOME LOWERING OF CLOUD BASES...AND TERMINALS SHOULD
SEE DEVELOPMENT OF MVFR CEILINGS THE NEXT FEW HOURS. A STRONG LOW
LEVEL JET OF 35-45KTS HAS PRODUCED LLWS OVER THE TERMINALS WHICH
SHOULD CONTINUE THROUGH APPROXIMATELY 12Z WHEN SURFACE WINDS
INCREASE. THE NEXT WAVE OF SHOWERS TO PUSH THROUGH THE TERMINALS
BEGINNING AROUND 09Z...BRINGING IFR-MVFR CEILINGS AND VISIBILITIES
FOR A FEW HOURS...BEFORE ONCE AGAIN RETURNING TO VFR. ANOTHER WAVE
OF SHOWERS WITH SOME THUNDERSTORMS WILL PUSH THROUGH THE TERMINALS
BEGINNING AROUND 15Z...AND MAY BRING A PERIOD OF THUNDER WITH MVFR
CEILINGS AND IFR VISIBILITIES WITH STRONGER CELLS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 70 47 58 40 / 80 80 20 0
INL 70 42 53 34 / 80 60 20 0
BRD 72 47 57 39 / 80 70 10 0
HYR 76 53 63 41 / 80 80 20 0
ASX 79 52 62 37 / 70 70 30 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...DAP
LONG TERM...BJT
AVIATION...LE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
350 AM CDT THU MAY 7 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM CDT THU MAY 7 2015
THE SHORT TERM CONCERNS ARE TIMING AND EXTENT OF CONVECTION AND
TEMPERATURES.
WATER VAPOR IMAGERY IS SHOWING SHORT WAVE TROUGH EXTENSION ACROSS
SOUTHEAST SOUTH DAKOTA INTO IOWA THIS MORNING. AREA OF SHOWERS AND
THUNDERSTORMS ASSOCIATED WITH THIS FEATURE...MOSTLY CONCENTRATED
ACROSS NORTHWEST IOWA/SOUTHWEST MINNESOTA. SPC MESOSCALE ANALYSIS
SHOWING DECENT 850MB MOISTURE TRANSPORT AHEAD OF THE TROUGH...WITH
MORE SHOWERS AND ISOLATED THUNDER DEVELOPING OUT ACROSS CENTRAL MN.
THIS SHOULD CONTINUE TO BE THE TREND AS THIS TROUGH LIFTS
NORTHEAST...AND THE MOISTURE TRANSPORT MAXIMIZES OVER MN. EXPECT AT
LEAST LIKELY POPS AS THIS LIFTS NORTHWEST. THE LATEST HRRR FORECAST
REFLECTIVITY SHOWS THIS TREND AS WELL.
CLOUDS ARE EXPECTED TO REMAIN...THOUGH SOME EROSION MAY OCCUR LATE
THIS MORNING BEFORE CONVECTION REFIRES...OR ENHANCES ONCE AGAIN.
DAY1 OUTLOOK HAS EXPANDED THE MARGINAL SEVERE WEATHER RISK OUT AHEAD
OF THE COLD FRONT. THIS WILL BE FOR THE AFTERNOON/EARLY EVENING
EAST OF THE COLD FRONT. STEEP LAPSE RATES INDICTED AND DEPENDING
HOW MUCH HEATING TAKES PLACE...MODEL FORECAST SURFACE BASED CAPE
INCREASING TO 1500 J/KG. BULK SHEAR IS FORECAST TO RANGE 35-40KTS
ALONG AND EAST OF THE FRONT...WHICH WOULD BE ENOUGH FOR THE
POSSIBILITY OF HAIL AND STRONG WINDS WITH THE STRONGER CONVECTION.
THE MODELED UPDRAFT HELICITY WAS INDICATING THE MAIN THREAT OVER
WEST CENTRAL WISCONSIN...WITH WHAT APPEARS TO BE A LEADING SURFACE
TROUGH. WILL HAVE TO MONITOR CLOUD TRENDS AND SEE IF INDEED
INSTABILITY WILL INCREASE ENOUGH TO GENERATE A SMALL SEVERE WEATHER
RISK OVER THE EASTERN CWA.
THE FRONT MOVES INTO WESTERN WISCONSIN THIS EVENING AND SHOULD TAKE
THE BULK OF THE SHOWERS WITH IT. THERE IS SOME THREAT OF MID LEVEL
SHRA DEVELOPING BEHIND THE COLD FRONT INTO CENTRAL MN LATER TONIGHT.
THE MODELS WERE INDICATING SOME STRONGER MID LEVEL FGEN. BUT IT
REMAINS TO BE SEEN IF THERE WILL BE ENOUGH MOISTURE TO CONTINUE THE
SHOWER THREAT. STILL MAINTAINED THE SMALL CHANCE POPS AFTER 06Z
FRI FOR NOW.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 350 AM CDT THU MAY 7 2015
BY FRIDAY MORNING...THE AFOREMENTIONED COLD FRONT AND SURFACE LOW
RESPONSIBLE FOR THE RAIN IN THE SHORT TERM WILL BE EAST OF THE
FORECAST AREA. HIGH PRESSURE WILL BUILD IN ACROSS THE NORTHERN
HIGH PLAINS ON FRIDAY AND INTO THE UPPER MISSISSIPPI RIVER VALLEY
ON SATURDAY. THE POST FRONTAL AIR MASS ON FRIDAY WILL BE QUITE
COOL WITH TEMPERATURES IN CENTRAL/NORTHERN MN LIKELY REMAINING IN
THE 50S DURING THE AFTERNOON. WE MIGHT EVEN BE A LITTLE TOO WARM
WITH FRIDAY`S TEMPERATURES...ESPECAILLY GIVEN THE DECENT CHANCE
FOR A BROKEN TO OVERCAST DECK OF MID CLOUDS. THE WEATHER SHOULD
REMAIN DRY ON FRIDAY. ON SATURDAY...A WEST COAST TROUGH WILL EJECT
EAST OUT OF CALIFORNIA AND PASS OVER THE ROCKIES BEFORE SLOWLY
MAKING ITS TRACK ACROSS THE REGION SUN-TUE. A SURFACE LOW IS
FORECAST TO TRACK FROM THE CENTRAL PLAINS...ACROSS IA...AND
EVENTUALLY REACHING EASTERN LAKE SUPERIOR BY TUESDAY. THAT PUTS
MN/WI IN A PRETTY GOOD SPOT FOR WIDESPREAD RAIN SUNDAY INTO
MONDAY. THE 06.18Z AND 07.00Z RUNS OF THE GFS DEPICT SIMILIAR
SOLUTIONS...A CHANGE FROM THE FEW RUNS BEFORE THESE LAST TWO WHICH
HAD A LOT OF RUN-TO-RUN VARIABILITY IN HOW IT HANDLED THE
PROGRESSION OF THIS SURFACE LOW EARLY NEXT WEEK. THE GFS IS
HEAVIER WITH THE QPF WHEN COMPARED TO THE ECMWF...BECAUSE IT IS
ALSO SLOWER...DEEPER...AND FARTHER SOUTH THAN THE ECMWF. THE ECMWF
HAS ALSO HAD A COUPLE RUNS NOW WITH BETTER CONSISTENCY. WE TRENDED
THE TEMPS A BIT COOLER MON-WED...WITH THE FREEZING LEVEL JUST A
COUPLE THOUSAND FEET OFF THE GROUND TUE-WED. TEMPERATURES REALLY
DO NOT START TO MODIFY UNTIL AT LEAST THURSDAY. SO...MN/WI IS IN
FOR A COOL WEEK AFTER THE RAIN MOVES TUE-TUE NIGHT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 1020 PM CDT WED MAY 6 2015
WAITING FOR THE NEXT BATCH OF SHOWERS AND THUNDERSTORMS TO LIFT
NORTHEAST FROM EASTERN NE AND NORTHWEST IA. THIS ACTIVITY WILL
WANE A BIT...BUT WILL OVERSPREAD THE AREA LATE TONIGHT AND
THURSDAY MORNING. BKN-OVC MVFR CIGS WILL DEVELOP AS THIS AREA
ARRIVES. THEN EXPECT A BREAK DURING THE AFTERNOON...WITH
POTENTIAL FOR MORE DEVELOPMENT /THUNDERSTORMS/ LATE AFTERNOON.
SOUTHEAST WINDS SHIFT TO THE SOUTHWEST ON THURSDAY...THEN TO THE
NORTHWEST ON THURSDAY EVENING. SPEEDS AOA 12KTS THROUGH THE
PERIOD.
KMSP...
MAINLY DRY OVERNIGHT...UNTIL NE/IA BATCH OF PRECIPITATION MOVES
IN. EXPECT THIS AROUND/AFTER 12Z...PERSISTING THROUGH THE MORNING
ALONG WITH MVFR CONDITIONS /BUT SHOULD STAY ABOVE 1700 FT/. BRIEF
BREAK IN THE EARLY AFTERNOON...THEN REDEVELOPMENT /POSSIBLY WITH
THUNDER/ OCCURS BY LATE AFTERNOON.
/OUTLOOK FOR KMSP/
FRI...VFR. WINDS NW 10 KTS.
SAT...VFR. WINDS NE 10 KTS.
SUN...MVFR LIKELY WITH IFR POSSIBLE IN SHWRS/TSTMS. WINDS NE 10-15
KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...DWE
LONG TERM...CLF
AVIATION...LS
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
411 AM CDT Thu May 7 2015
.SHORT TERM: (Today and Tonight)
Issued at 339 AM CDT Thu May 7 2015
Short-range guidance has been consistently spitting out some sunrise
surprise showers for the past few runs. The RAP might be a little
overdone as it looks like it`s trying to break pieces of the MCV
currently over Oklahoma off and spread them northeast across the
area. That being said, radar is picking up some very light echos
developing over the eastern Ozarks at this time...so the possibility
for isolated showers does seem to be increasing this morning.
Aside from any morning showers, expect most of the morning and early
afternoon to be dry. Should see highs today similar to if not a bit
warmer than Wednesday. The MCV should lift up into the area and
provide a lifting mechanism later this afternoon. Additionally,
the cold front now over western Nebraska/Kansas will drift into
western/northwestern Missouri by late this afternoon providing an
additional focusing mechanism. Think likely PoPs across central and
northeast Missouri into west central Illinois look good with chance
PoPs further to the southeast still look good for the afternoon into
early evening. PoPs for the rest of the night are less certain
though, and short-range guidance seems to be having as much trouble
as I am figuring out how to handle the situation. MOS guidance
ranges from low chance to categorical across the area. GFS and NAM
do show a weak to moderate low level jet setting up during the
evening, with a few waves of moisture convergence in the warm sector
ahead of the front. Baroclinicity is weak, but present, so I cannot
rule out scattered to possibly numerous showers and
thunderstorms...particularly closer to the front in central and
northeast Missouri.
Carney
.LONG TERM: (Friday through Wednesday)
Issued at 410 AM CDT Thu May 7 2015
Southwest flow aloft will continue to try to bring deeper moisture
back to the Mississippi Valley Friday into the weekend. It`s
difficult to really pick out a time when thunderstorms are more or
less likely for Friday through Sunday as the foci for precipitation
will likely be fast-moving shortwaves moving over the area in the
southwest flow aloft, as well as low level boundaries from
convection. Models have the synoptic front generally draped across
northern Missouri...possibly dipping down as far south as the
Missouri river at times as it is forced south by convection. Have
some flavor of 40-70% PoPs across the area for Friday through
Saturday night with the higher end PoPs closer to the synoptic
front. Guidance has the high amplitude closed wave finally opening
up and moving int the Great Plains on Sunday with the resulting
surface low moving northeast from Kansas through Iowa into the Great
Lakes Sunday night through Monday. Resulting cold front should
sweep through the forecast area late Sunday night into early Monday
morning. Cooler and drier air will bring an end to the rain chances
by most likely by Monday afternoon. Above normal temperatures will
continue ahead of the FROPA on Monday with highs mainly in the 80s
and lows in the mid 60s. Medium range guidance drops temperatures
back below normal for Tuesday and Wednesday showing highs mainly 65
to 70 and lows mainly in the upper 40s and low 50s.
Carney
&&
.AVIATION: (For the 06z TAFs through 06z Thursday Night)
Issued at 1053 PM CDT Wed May 6 2015
Just mid-high level cloudiness late tonight. Diurnal cumulus clouds
will develop again late Thursday morning and afternoon with
scattered showers and storms expected as an upper level
disturbance moves through the area with a moist and unstable
atmosphere. Will include VCTS for the taf sites for Thursday
afternoon into the evening. S-sely surface winds late tonight,
then gusty sly winds on Thursday.
Specifics for KSTL: Just some mid-high level clouds late tonight,
then diurnal cumulus clouds will develop late Thursday morning and
afternoon with isolated to scattered showers/storms for late
Thursday afternoon and evening. S-sely surface wind late tonight,
becoming strong and gusty again from a sly direction on Thursday.
The surface wind will weaken Thursday night.
GKS
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 86 68 84 68 / 30 50 70 40
Quincy 83 65 79 62 / 60 60 70 50
Columbia 82 65 78 64 / 60 60 70 50
Jefferson City 84 65 80 65 / 60 60 70 50
Salem 85 66 84 67 / 20 20 50 50
Farmington 84 65 81 65 / 30 50 60 40
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
340 AM CDT Thu May 7 2015
.SHORT TERM: (Today and Tonight)
Issued at 339 AM CDT Thu May 7 2015
Short-range guidance has been consistently spitting out some sunrise
surprise showers for the past few runs. The RAP might be a little
overdone as it looks like it`s trying to break pieces of the MCV
currently over Oklahoma off and spread them northeast across the
area. That being said, radar is picking up some very light echos
developing over the eastern Ozarks at this time...so the possibility
for isolated showers does seem to be increasing this morning.
Aside from any morning showers, expect most of the morning and early
afternoon to be dry. Should see highs today similar to if not a bit
warmer than Wednesday. The MCV should lift up into the area and
provide a lifting mechanism later this afternoon. Additionally,
the cold front now over western Nebraska/Kansas will drift into
western/northwestern Missouri by late this afternoon providing an
additional focusing mechanism. Think likely PoPs across central and
northeast Missouri into west central Illinois look good with chance
PoPs further to the southeast still look good for the afternoon into
early evening. PoPs for the rest of the night are less certain
though, and short-range guidance seems to be having as much trouble
as I am figuring out how to handle the situation. MOS guidance
ranges from low chance to categorical across the area. GFS and NAM
do show a weak to moderate low level jet setting up during the
evening, with a few waves of moisture convergence in the warm sector
ahead of the front. Baroclinicity is weak, but present, so I cannot
rule out scattered to possibly numerous showers and
thunderstorms...particularly closer to the front in central and
northeast Missouri.
Carney
.LONG TERM: (Friday Night through Next Wednesday) Issued at 355 PM
CDT Wed May 6 2015
Meanwhile, a large low pressure system will be dropping southward
along the west coast before briefly closing off over CA and then
migrating slowly eastward through the desert southwest. This
feature then lifts northeastward into the plains and induces lee
cyclogenesis near the OK/TX panhandles on Saturday. A trailing
cold front will have nosed into northern MO and stalled on Friday
night when the flow aloft becomes parallel to the boundary, but
the developing surface low will start to lift the boundary back
northward on Saturday as a warm front. There is still some
question regarding how far south the boundary will progress before
it starts to lift back to the north, and this could affect both
high temperatures and precipitation chances for parts of the CWA.
Much like the low pressure system which was moving slowly
northeastward late this afternoon, the aforementioned low pressure
system is also forecast to move slowly northeastward with time
over the weekend, which will keep periodic SHRA/TSRA chances in
the forecast through the weekend and into early next week. The
cold front associated with this system finally pushes through the
area on Sunday night and Monday. High pressure builds in behind
the front on Monday night, and precipitation chances diminish
accordingly.
Recent models runs are in general agreement that 0-6 km shear
remains fairly weak across the LSX CWA, at least until Sunday/Sunday
night into Monday when models show it increasing to around 30-50
kts. This suggests that although a few strong storms are possible
over the next few days, widespread severe weather is unlikely. Later
shifts will need to keep an eye on the evolution of the
Sunday/Monday system and the potential for severe weather given
the forecast values of shear and instability ahead of the
approaching cold front.
Temperatures will remain unusually warm through the weekend
followed by cooler temperatures early next week behind the cold
front.
Kanofsky
&&
.AVIATION: (For the 06z TAFs through 06z Thursday Night)
Issued at 1053 PM CDT Wed May 6 2015
Just mid-high level cloudiness late tonight. Diurnal cumulus clouds
will develop again late Thursday morning and afternoon with
scattered showers and storms expected as an upper level
disturbance moves through the area with a moist and unstable
atmosphere. Will include VCTS for the taf sites for Thursday
afternoon into the evening. S-sely surface winds late tonight,
then gusty sly winds on Thursday.
Specifics for KSTL: Just some mid-high level clouds late tonight,
then diurnal cumulus clouds will develop late Thursday morning and
afternoon with isolated to scattered showers/storms for late
Thursday afternoon and evening. S-sely surface wind late tonight,
becoming strong and gusty again from a sly direction on Thursday.
The surface wind will weaken Thursday night.
GKS
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 86 68 84 68 / 30 50 70 40
Quincy 83 65 79 62 / 60 60 70 50
Columbia 82 65 78 64 / 60 60 70 50
Jefferson City 84 65 80 65 / 60 60 70 50
Salem 85 66 84 67 / 20 20 50 50
Farmington 84 65 81 65 / 30 50 60 40
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
320 AM CDT THU MAY 7 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 318 AM CDT THU MAY 7 2015
SHOWERS AND THUNDERSTORMS CONTINUE MAINLY ACROSS THE SOUTHEAST PART
OF THE FORECAST AREA. SURFACE ANALYSIS SHOWS A LOW PRESSURE SYSTEM
AND COLD FRONT JUST TO THE WEST OF THE FORECAST AREA AT THIS TIME.
MODELS ARE FAIRLY CONSISTENT KEEPING THE CURRENT PRECIPITATION
ACROSS MAINLY THE EASTERN PART OF THE FORECAST AREA THROUGH DAYBREAK
OR INTO THE MORNING HOURS...BUT WHEN IT MOVES OUT THERE SHOULD BE A
BREAK IN THE PRECIPITATION FOR A TIME. THE COLD FRONT TO THE WEST OF
THE FORECAST AREA THIS MORNING IS EXPECTED TO MOVE THROUGH THE AREA
DURING THE DAY. MODELS HAVE SOME DIFFERENCES ON HOW FAST IT MOVES
THROUGH. THE GFS HAS IT MOST OF THE WAY THROUGH THE FORECAST AREA BY
MID DAY WHILE THE NAM IS SLOWER TO MOVE THROUGH. THE RAP IS CLOSER
TO THE GFS AND MOVES IT THROUGH FASTER. WENT A LITTLE IN BETWEEN AND
HAVE IT IN THE EAST AND SOUTHERN PARTS OF THE FORECAST AREA MID
AFTERNOON. THE LOCATION OF THE FRONT IS IMPORTANT AS THE NEXT UPPER
LEVEL WAVE MOVES INTO THE FORECAST AREA DURING THE LATE AFTERNOON
AND INTO TONIGHT. THE UPPER WAVE MOVES IN FROM THE SOUTHWEST SO THE
PRECIPITATION SHOULD MOVE IN FROM THE SOUTH DURING THE AFTERNOON AND
SPREAD ACROSS MUCH OF THE AREA. THE BEST CHANCES WILL BE IN THE
SOUTH OR SOUTHEAST TONIGHT. WILL HAVE TO WATCH THE SOUTHEAST...THIS
IS THE AREA WITH ONGOING FLOODING AND THE AREA THE MOST LIKELY TO
HAVE PRECIPITATION TONIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 318 AM CDT THU MAY 7 2015
GUIDANCE SUGGESTS AN UPPER TROPOSPHERIC LOW WILL EXIST OVER THE
SOUTHWESTERN CONUS TO START THE LONG-TERM FORECAST PERIOD AT 12Z
FRIDAY...WITH UPPER TROPOSPHERIC RIDGING OVER THE EASTERN CONUS.
THIS UPPER TROPOSPHERIC LOW IS EXPECTED TO MOVE NORTHEAST FRIDAY
THROUGH EARLY NEXT WEEK...LIKELY CLEARING THE CENTRAL PLAINS
SATURDAY INTO SUNDAY. QUASI-ZONAL UPPER TROPOSPHERIC FLOW IS THEN
EXPECTED ACROSS THE REGION DURING THE EARLY TO MIDDLE PART OF NEXT
WEEK.
GUIDANCE SUGGESTS UPPER TROPOSPHERIC THERMAL ADVECTION AHEAD OF THE
APPROACHING LOW WILL PROMOTE PRECIPITATION PRODUCTION ACROSS OUR AREA
FRIDAY THROUGH EARLY NEXT WEEK...WITH PERHAPS A RELATIVELY DRY
PERIOD AT SOME POINT EARLY NEXT WEEK AS THE AFOREMENTIONED UPPER
TROPOSPHERIC LOW CLEARS THE REGION. THAT SAID...GUIDANCE ALSO
SUGGESTS MULTIPLE UPPER TROPOSPHERIC PERTURBATIONS...EMBEDDED WITHIN
THE DEVELOPING QUASI-ZONAL FLOW...COULD PROMOTE ADDITIONAL
PRECIPITATION CHANCES DURING THE MIDDLE TO LATE PART OF NEXT WEEK.
GIVEN ALL THIS...POPS REMAIN INTACT ACROSS THE AREA DURING MUCH OF
THE LONG-TERM FORECAST PERIOD...WITH THE HIGHEST POPS EXISTING
BETWEEN SATURDAY AFTERNOON AND SATURDAY NIGHT AS THE UPPER
TROPOSPHERIC LOW CLEARS THE AREA.
A DRIER BOUNDARY-LAYER AIR MASS...ALONG WITH MODEST UPPER
TROPOSPHERIC LAPSE RATES...SHOULD KEEP SEVERE WEATHER AT BAY FRIDAY
INTO FRIDAY NIGHT...WITH GUIDANCE SUGGESTING POTENTIAL ENERGY WILL
REMAIN AT OR BELOW 500J/KG ACROSS MUCH OF THE CWA. THAT WILL CHANGE
FOR PORTIONS OF THE REGION SATURDAY INTO SATURDAY NIGHT HOWEVER AS
BOUNDARY-LAYER MOISTURE FLUX ACROSS THE CENTRAL PLAINS...ALONG WITH
INCREASING UPPER TROPOSPHERIC LAPSE RATES WITH THE APPROACH OF THE
UPPER TROPOSPHERIC LOW...PROMOTES POTENTIAL ENERGY ON THE ORDER OF
~1500J/KG ACROSS SOUTHERN PORTIONS OF THE CWA...AND LOWER POTENTIAL
ENERGY AS ONE MOVES NORTH ACROSS THE AREA. THESE POTENTIAL ENERGY
VALUES...WORKING IN CONCERT WITH DEEP-LAYER BULK SHEAR VALUES OF
AROUND 50KTS...COULD PRESENT YET ANOTHER OPPORTUNITY FOR SEVERE
WEATHER ACROSS PORTIONS OF THE CWA SATURDAY AFTERNOON INTO SATURDAY
NIGHT...ESPECIALLY ACROSS OUR SOUTHERN COUNTIES SOUTH OF HIGHWAY 6.
GIVEN THIS...WILL CONTINUE MENTIONING SEVERE WEATHER IN THE HWO
SATURDAY INTO SATURDAY NIGHT GENERALLY SOUTH OF HIGHWAY 6. DRIER
BOUNDARY-LAYER AIR AND DECREASING UPPER TROPOSPHERIC LAPSE RATES
SHOULD THEN ALLOW FOR A DECREASING SEVERE WEATHER THREAT AS WE MOVE
INTO THE EARLY PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1222 AM CDT THU MAY 7 2015
THE THUNDERSTORM ACTIVITY IS SOUTH OF THE TERMINAL AREAS AND
SHOULD STAY TO THE SOUTH. MID LEVEL CLOUDS WILL CONTINUE THROUGH
THE MORNING HOURS AND SHOULD START TO MOVE OUT DURING THE
AFTERNOON. A COLD FRONT WILL BE MOVING THROUGH THE AREA AND THE
WINDS SHOULD TURN FROM SOUTH TOWARD THE SOUTHWEST AND EVENTUALLY
TO THE NORTHWEST.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...JCB
LONG TERM...BRYANT
AVIATION...JCB
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1006 PM PDT WED MAY 6 2015
.SYNOPSIS...INCREASINGLY BREEZY CONDITIONS WILL DEVELOP THROUGH
THURSDAY AS A STRONG AND COLD LOW PRESSURE SYSTEM BEGINS TO MOVE
TOWARD SOUTHERN CALIFORNIA AND SOUTHERN NEVADA. SHOWERS AND
THUNDERSTORMS ARE POSSIBLE AREA WIDE FRIDAY AS THE LOW MOVES OVER
THE REGION WITH TEMPERATURES WELL BELOW NORMAL. DRY AND WARMER
CONDITIONS ARE EXPECTED SUNDAY INTO EARLY NEXT WEEK.
&&
.UPDATE...WHAT IS LEFT OF A LINE OF SHOWERS (THAT EARLIER ALSO
CONTAINED THUNDERSTORMS) CONTINUES TO PROGRESS EAST THIS EVENING
ACROSS ESMERALDA AND CENTRAL NYE COUNTIES. HOWEVER, WITH THE LOSS OF
HEATING THIS ACTIVITY CONTINUES TO BE ON A DOWNWARD TREND. INFRARED
SATELLITE STILL SHOWS SOME BRIGHTER CLOUD TOPS SO A LIGHTNING STRIKE
OR TWO MAY STILL DEVELOP BUT BASED ON RECENT TRENDS THE FORECAST WAS
LEFT AS JUST SHOWERS FOR THE OVERNIGHT PERIOD. THE HRRR CONTINUES TO
SLOWLY WEAKEN THIS CONVECTION THROUGH THE REST OF THE NIGHT ACROSS
CENTRAL NYE COUNTY. THE GRIDS WERE UPDATED A BIT TO ACCOUNT FOR
RECENT AREAL COVERAGE TRENDS WITH THIS ACTIVITY, OTHERWISE NO OTHER
CHANGES WERE MADE TO THE ONGOING FORECAST.
&&
.AVIATION...FOR MCCARRAN...GUSTY SOUTH-SOUTHWEST WINDS AT TIMES TO
15-20 KTS ARE EXPECTED OVERNIGHT WITH SUSTAINED WINDS AVERAGING 8-12
KTS. SOUTH-SOUTHWEST WINDS AT 8-14 KTS IN THE MORNING WILL INCREASE
TO 15-20 KTS WITH GUSTS OF 25-30 KTS IN THE AFTERNOON AND EVENING.
CLEAR OVERNIGHT WITH SCT-BKN CLOUDS AOA 10-15K FEET ON THURSDAY
ESPECIALLY IN THE AFTERNOON AND EVENING. ISOLATED SHRA/TSRA POSSIBLE
AFTER 20Z THURSDAY THROUGH 04Z FRIDAY IN THE MOUNTAINS.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...LINGERING SHRA AND CLOUD BASES TO 8K-12K FEET UNTIL
AROUND 08Z THURSDAY ACROSS ESMERALDA AND CENTRAL NYE COUNTIES.
OTHERWISE A CLEAR SKY OVERNIGHT WITH WINDS 6-12 KTS FAVORING TYPICAL
DIURNAL DIRECTIONAL TRENDS EXCEPT IN AND AROUND KDAG WHICH WILL STAY
SOUTHWEST TO WEST AT 15-25 KTS WITH GUSTS OF 20-30 KTS. WINDS WILL
INCREASE FROM THE SOUTH TO SOUTHWEST ACROSS THE AREA BY THURSDAY
AFTERNOON AND REMAIN GUSTY INTO THE EVENING WITH SPEEDS SUSTAINED AT
15-25 KTS WITH GUSTS OF 20-30 KTS EXCEPT IN AND AROUND KDAG WHERE
SUSTAINED WINDS OF 25-35 KTS WITH GUSTS OF 35-45 KTS POSSIBLE. LOCAL
AREAS OF BLDU MAY OCCUR REDUCING VSBY. OTHERWISE EXCEPT SCT-BKN
CLOUDS AOA 6K-12K FEET WITH SHRA/TSRA POSSIBLE ALONG AND NORTH OF
KEDW-KDRA-KIGM LINE. GUSTY AND ERRATIC WINDS POSSIBLE NEAR ANY
SHRA/TSRA OR OUTFLOW BOUNDARIES.
.PREV DISCUSSION... 247 PM PDT WED MAY 6 2015
.SHORT TERM...THROUGH FRIDAY NIGHT.
AS THE COLD CORE DIGS OVER CENTRAL CALIFORNIA THURSDAY...THIS WILL
PLACE INYO AND ESMERALDA COUNTIES CLOSE TO THE EASTERN SIDE OF THE
CORE THROUGH THURSDAY AFTERNOON THEN THE LOW CENTER IS FORECAST TO
TRACK DIRECTLY ACROSS THE SOUTHERN SIERRA AND OVER SOUTHERN NEVADA
FRIDAY. THIS WILL LEAD TO SIGNIFICANT SNOWFALL IN THE SOUTHERN
SIERRA AND A WINTER WEATHER ADVISORY HAS BEEN ISSUED ABOVE 6000
FEET. THE OTHER IMPACT OF THE SYSTEM WILL BE GUSTY SOUTH TO
SOUTHWEST WINDS ACROSS MUCH OF THE REGION THURSDAY AFTERNOON AND
EVENING. GUSTS OF 30 TO 40 MPH WILL BE COMMON BUT ADVISORY LEVEL
WINDS LOOK MARGINAL AND IT DOES NOT APPEAR TO HAVE THE POTENTIAL OF
PRODUCING WIDESPREAD BLOWING DUST SO NO WIND ADVISORIES ARE PLANNED
FOR NOW.
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL OCCUR ACROSS
THE REST OF THE REGION FRIDAY THROUGH FRIDAY EVENING BUT CONFIDENCE
IS LOW IN SIGNIFICANT SNOWFALL FOR THE SPRING MOUNTAINS SO NO OTHER
ADVISORIES ARE PLANNED FOR NOW. HIGH TEMPERATURES COULD BE THE
COOLEST SINCE EARLY MARCH WITH READINGS IN THE LOW TO MID 60S
EXPECTED IN LAS VEGAS FRIDAY.
.LONG TERM...SATURDAY THROUGH TUESDAY.
EVEN AS MAIN LOW SHIFTS EAST INTO THE FOUR CORNERS REGION SATURDAY,
MODELS INSIST ADDITIONAL ENERGY MOVING SOUTH WITHIN BACKSIDE OF
TROUGH WILL KEEP A CHANCE OF SHOWERS AND A FEW THUNDERSTORMS ACROSS
MAINLY SOUTHERN NEVADA AND INYO COUNTY SATURDAY. FOR SUNDAY, ANY
REMAINING INSTABILITY WILL CONFINE ISOLATED SHOWERS TO EASTERN
LINCOLN AND NORTHERN MOHAVE COUNTIES. DRY/STABLE AIR MASS ASSOCIATED
WITH RIDGING WILL START BUILDING IN FROM THE WEST. RIDGE QUICKLY
SHIFTS EAST MONDAY AS WINDS ALOFT BACK SOUTHWESTERLY ON TUESDAY
AHEAD OF NEXT TROUGH DEVELOPING NEAR THE PAC NW COAST. THERE IS SOME
SPREAD IN THE POSITIONING OF THIS NEXT TROUGH. AFTER THE DRAMATIC
COOL DOWN FRIDAY, TEMPERATURES WILL STEADILY WARM DURING THE PERIOD
RETURNING TO NORMAL OR SLIGHTLY ABOVE NORMAL MONDAY AND TUESDAY.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION IS NOT EXPECTED
AT THIS TIME HOWEVER...SPOTTERS ARE ENCOURAGED TO REPORT ANY
SIGNIFICANT WEATHER CONDITIONS THIS WEEK ACCORDING TO STANDARD
OPERATING PROCEDURES.
&&
$$
UPDATE/AVIATION...STACHELSKI
SHORT TERM...ADAIR
LONG TERM...PIERCE
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
356 AM EDT THU MAY 7 2015
.SYNOPSIS...
LOW PRESSURE SOUTH OF CAPE FEAR MAY BECOME A SUBTROPICAL CYCLONE
OVER THE NEXT COUPLE OF DAYS. THE SYSTEM IS EXPECTED TO APPROACH
THE COAST OF SOUTH CAROLINA OR SOUTHERN NORTH CAROLINA FRIDAY AND
SATURDAY WITH INCREASING CHANCES FOR HEAVY RAIN...GUSTY WINDS...
AND DANGEROUS RIP CURRENTS AT THE BEACHES. THIS SYSTEM WILL ONLY
GRADUALLY LIFT NORTH AWAY FROM THE AREA EARLY NEXT WEEK. A COLD
FRONT WILL APPROACH NEXT WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM THURSDAY...EXTENSIVE RAIN SHIELD APPROACHING AND NOW
SKIRTING THE COAST IS HAVING TROUBLE HOLDING TOGETHER OVER LAND AS
IT HAS TO OVERCOME A VERY DRY MID LAYER. THE TEMP-DEWPOINT SPREAD
AT THE 850 MB LEVEL IS AROUND 45 DEGREES JUST INLAND OF THE
COASTAL COUNTIES THIS MORNING ACCORDING TO MODEL SOUNDINGS...SO
ALTHOUGH THE BEACHES ARE FINALLY SEEING SOME PATCHY LIGHT RAIN
WITH CIGS AROUND 10 KFT...PROGRESS FURTHER WESTWARD WILL CONTINUE
TO BE SLOW AND UNEVEN. RADAR SHOWS A NARROW BAND OF HEAVIER RAIN
ABOUT 20 NM OFFSHORE. UNLESS THAT BAND GETS HERE INTACT WE CAN
EXPECT ANY ACCUMULATIONS TO BE ONLY ON THE VERY LIGHT SIDE THIS
MORNING.
NHC NOW HAS THE NON-TROPICAL LOW PRESSURE SYSTEM AROUND 220 MILES
SSE OF THE SC/NC BORDER AND GIVES A 70 PERCENT CHANCE OF CYCLONE
FORMATION WITHIN 48 HOURS. SATELLITE LOOPS SHOW BETTER ORGANIZATION
AND A MORE DISTINCT CIRCULATION CENTER...WHICH IS BEING ANALYZED AT
AROUND 1009 MB. GUIDANCE IN REL GOOD AGREEMENT FOR THE NEAR TERM AS
FAR AS MOVEMENT GOES...WITH THE SYSTEM DRIFTING NW TOWARDS COASTAL
NC/SC. ALL MODELS SHOW DEEPENING WITH THE NAM BEING THE MOST
AGGRESSIVE. HAVE LEANED ON A BLEND OF GUIDANCE TO ACCOUNT FOR BOTH
THE UNCERTAINTY OF THE SITUATION AND AGREEMENT BETWEEN GUIDANCE.
EXPECT WINDS TO PICK UP FROM THE NE TODAY AS THE SYSTEM MOVES
NW...BUT THE RELATIVELY MODERATE ASSOCIATED GRADIENT WILL KEEP WINDS
IN THE 15 KT RANGE THIS AFTERNOON WITH GUSTS OF 20 KTS OR SO. PRECIP
WILL BE THE TRICKY ELEMENT OF THE FORECAST. GIVEN RECENT TRENDS AND
PROJECTED MOVEMENT OF THE SYSTEM HAVE UPPED POPS TO CATEGORICAL FOR
TODAY FOR THE COASTAL COUNTIES...TRENDING DOWNWARD AS ONE MOVES
INLAND. RETAINING POSSIBILITY OF THUNDER OVERNIGHT AS SYSTEM
APPROACHES THE COAST.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 330 AM THURSDAY...THE CHALLENGE...UNSURPRISINGLY...THROUGH
THE SHORT TERM REMAINS DETERMINING WHAT KIND OF IMPACT A
STRENGTHENING LOW PRESSURE WILL HAVE ON THE AREA. RECON FROM NHC
WAS CANCELLED YESTERDAY AFTN DUE TO LACK OF ORGANIZATION...AND
CURRENT WV/IR IMAGERY IS LESS THAN IMPRESSIVE...ALTHOUGH
IMPROVING. HOWEVER...GUIDANCE IS STARTING TO COME TO SOME GENERAL
CONSENSUS ON A SLOWER AND OVERALL WEAKER SYSTEM MEANDERING JUST
OFF THE COAST THROUGH THE PERIOD. LOW PRESSURE WILL LIFT NORTH TO
SOME WHERE JUST OFF THE SC COAST BEFORE THE PERIOD...AND THEN
STALL...LOOP...OR RETROGRADE BACK TOWARDS THE SW AS ITS MOTION
GETS HALTED BY RIDGE TO THE NORTH. VERY SLOW MOVEMENT IS EXPECTED
REGARDLESS OF THE ACTUAL TRACK...AND IT IS NEARLY GUARANTEED THAT
THIS WILL BE IMPACTING THE AREA ALL FRIDAY AND SATURDAY. A SLOWLY
LOOPING SYSTEM JUST OFFSHORE WILL MAINTAIN RAIN CHANCES...SOME OF
WHICH MAY BE HEAVY AT TIMES...THE CHANCE FOR SOME GUSTY WINDS
(FOCUSED ALMOST EXCLUSIVELY ALONG THE COAST HOWEVER)...AS WELL AS
HIGH WAVE ACTION/MINOR BEACH EROSION/STRONG RIP CURRENTS.
THE BIGGEST IMPACT LOCALLY IS LIKELY TO END UP BEING
RAINFALL...ESPECIALLY FROM MYRTLE BEACH NORTHWARD ACROSS THE CAPE
FEAR COAST. GUIDANCE SUGGESTING THAT 250MB DIFFLUENCE WILL BE ALMOST
EXCLUSIVELY ON THE N AND E SIDE OF THE SYSTEM (MORE EVIDENT IT WILL
NEVER TRULY BECOME TROPICAL EVEN AS FSU PHASE DIAGRAMS SUGGEST
SYMMETRIC WARM CORE DEVELOPMENT) WHICH SUGGESTS CONVECTION WILL BE
CONFINED TO THE N/E SIDE OF THE SYSTEM. WITH THE LOW STALLING JUST
SE OF THE AREA...COPIOUS MOISTURE WILL ADVECT FROM AN ANOMALOUSLY
HIGH PWAT AIRMASS...SO SOME VERY HEAVY RAIN WILL AT LEAST LURK
OFFSHORE...AND MAY ADVECT INLAND. A TIGHT AND SIGNIFICANT GRADIENT
WILL EXIST...AND CONVECTIVE ELEMENTS ARE POSSIBLE AS MOIST-ADIABATIC
LAPSE RATES EXIST DEEP INTO THE COLUMN. HIGHEST POP WILL REMAIN
FRIDAY ESP ALONG THE COAST...BUT A GOOD CHC FOR RAINFALL WILL
CONTINUE RIGHT TROUGH SATURDAY NIGHT.
TEMPS WILL STRUGGLE EVEN IN THE TROPICAL AIR MASS DUE TO WIDESPREAD
CLOUDS AND RAIN. HIGHS WILL REMAIN BELOW CLIMO...MID 70S FRIDAY AND
UPR 70S SATURDAY...BUT TEMPERED DIURNAL RANGES WILL KEEP MINS IN THE
UPR 60S OR CLOSE TO 70 BOTH NIGHTS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 330 AM THURSDAY...FIRST HALF OF THE EXTENDED WILL CONTINUE
TO FEATURE A SLOW MOVING LOW PRESSURE SYSTEM SOMEWHERE IN THE
VICINITY. THIS LOW PRESSURE WILL MEANDER JUST OFFSHORE OR POSSIBLY
JUST INLAND OF THE COAST SUNDAY AND MONDAY AS STEERING FLOW
REMAINS GENERALLY WEAK. WHILE A WEAKENING TREND IS EXPECTED DURING
THE LONG TERM...THE HIGHEST PWAT AIR MAY ACTUALLY MOVE ACROSS THE
CWA SUNDAY...SO PERIODS OF HEAVY RAINFALL COULD CONTINUE AT LEAST
INTO MONDAY. WILL NOT FOCUS ON ANY SPECIFICS AT THIS TIME
RANGE...AND JUST SHOW CONTINUED UNSETTLED WEATHER WITH CHC
POP...HIGHEST ACROSS THE CAPE FEAR REGION...WITH PERIODS OF MDT TO
POSSIBLY HVY RAINFALL. THE LOW WILL FINALLY KICK OUT TO THE NE ON
TUESDAY AS AN UPPER TROUGH DIGS INTO THE GREAT LAKES REGION. THE
UNSETTLED CONDITIONS WILL PERSIST INTO WEDNESDAY HOWEVER AS A COLD
FRONT DIGS ACROSS THE CAROLINAS AT THE END OF THE PERIOD. THERE IS
GOOD NEWS HOWEVER...AS THIS FRONT SHOULD BRING IN A PERIOD OF MUCH
DRIER CONDITIONS BEYOND THIS FORECAST PERIOD.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
AS OF 06Z...CONFIDENCE IS STILL RATHER LOW...BUT IMPROVING AS THE
MODELS ARE STARTING TO GET A BIT MORE IN SYNC. LOW PRESSURE WILL
SLOWLY APPROACH THE REGION TOWARD MORNING...WITH SHOWERS AND MVFR
CONDITIONS EXPECTED AN HOUR OR TWO AFTER DAYBREAK ALONG THE COAST.
AGAIN...THE UNCERTAINTY IS THERE AS THE HRRR MODEL IS SLOWER THAN
THIS. THE GRADIENT WILL TIGHTEN ALSO AROUND DAYBREAK...WITH GUSTS
OVER 20 KTS A GOOD BET AFTER 14Z. THE INLAND TERMINALS WILL TAKE A
WHILE TO GET ANY PRECIP...PERHAPS BY MID AFTERNOON. THE COLUMN OF
DEEP MOISTURE WILL REMAIN OVER THE REGION THROUGH THE END OF THE
FORECAST PERIOD...WITH INTERMITTENT IFR POSSIBLE IN THE HEAVIER
PRECIP.
EXTENDED OUTLOOK...RAIN/MVFR. TEMPO IFR IN HEAVIER SHOWERS HIGHEST
CONFIDENCE COASTAL TERMINALS. BECOMING VFR/SHOWERS SUNDAY. VFR
ISOLATED SHOWERS MON.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM THURSDAY...SMALL CRAFT ADVISORY WILL CONTINUE
THROUGH THE NEAR TERM AS A LOW PRESSURE SYSTEM 220 MILES SSE OF
THE NC/SC BORDER DRIFTS NW. EXPECT WINDS AND SEAS TO BE HIGHEST
OVER OUR SC WATERS...WITH 20 TO 25 KTS AND 5 TO 8 FT RESPECTIVELY
FOR TODAY. CONDITIONS WILL BE A BIT BETTER FOR OUR NC WATERS...BUT
WILL STILL BE HAZARDOUS WITH SEAS IN THE 5 TO 7 FT RANGE.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 330 AM THURSDAY...STRENGTHENING LOW PRESSURE WILL MEANDER
VERY NEAR THE COASTAL WATERS THROUGH THE ENTIRE PERIOD...CREATING
PERIODS OF GUSTY WINDS AND LARGE WAVES. WHILE UNCERTAINTY REMAINS
IN THE EXACT INTENSITY AND PLACEMENT OF THIS SYSTEM AS IT
EVOLVES...REGARDLESS OF THE EVENTUAL SOLUTION CONDITIONS WILL BE
DIFFICULT FOR MARINERS. WITH THE CURRENT FORECAST PATH EXPECTED TO
KEEP THE LOW CENTER EAST OF THE SC...WINDS WILL BE GENERALLY
EASTERLY ACROSS AMZ250 AND AMZ252...AND NORTHERLY OVER AMZ254 AND
AMZ256. THESE SHOULD REMAIN FAIRLY CONSISTENT THROUGH THE
PERIOD...ALTHOUGH SOME FLUCTUATION CAN BE EXPECTED...ESPECIALLY AS
THE LOW WOBBLES IN THE VICINITY. SPEEDS REGARDLESS OF DIRECTION
WILL BE 15-25 KTS...WITH SOME GUSTS OVER 30 KTS
POSSIBLE...PRIMARILY OVER THE NC WATERS.
WAVE HEIGHTS WILL BE HIGHEST ACROSS NC WATERS THANKS TO THE ONSHORE
FLOW WHERE 5-9 FT SEAS ARE EXPECTED FRIDAY. 4-7 FTERS ARE
ANTICIPATED ACROSS THE SC WATERS. SEAS WILL GRADUALLY START TO COME
DOWN THE LATTER HALF OF THE PERIOD BUT THIS WILL OBVIOUSLY DEPEND ON
EXACTLY HOW THE SYSTEM EVOLVES BEYOND FRIDAY. ATTM SHOW WAVE HEIGHTS
LOWERING TO 3-5 FT SATURDAY AND THE CURRENT SCA ENDING AT 8AM
SATURDAY ACROSS THE SOUTHERN WATERS. NC SEAS WILL LIKELY REMAIN
ELEVATED BEYOND THE 8AM SCA END-TIME BUT WILL EXTEND AS NEEDED WITH
FUTURE UPDATES.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 330 AM THURSDAY...GUSTY WINDS TO START SUNDAY...ESPECIALLY
ACROSS THE NC WATERS...AS THE PERSISTENT LOW PRESSURE SYSTEM MOVES
SLOWLY NEAR THE AREA. ATTM THE BEST FORECAST TAKES THE LOW INLAND
ACROSS HORRY/BRUNSWICK COUNTIES...AND THUS WINDS THE FIRST HALF OF
SUNDAY WILL STILL BE GUSTY AROUND 20 KTS FROM THE EAST ACROSS
AMZ250/252...BUT MUCH WEAKER AND NORTHERLY OVER THE SC WATERS. THIS
SYSTEM WILL FINALLY BEGIN TO LIFT NE THROUGH SUNDAY AND INTO
MONDAY...SO WINDS WILL VEER TO THE SW AND BECOME 10-15 KTS ACROSS
ALL THE COASTAL WATERS. SEAS INITIALLY MAY STILL BE ABOVE SCA
THRESHOLDS ACROSS THE NC WATERS BUT SHOULD FALL THROUGH THE
DAY...AND 3-4 FT SEAS ARE FORECAST FOR MOST OF THE EXTENDED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT SATURDAY FOR
AMZ250-252-254-256.
&&
$$
SYNOPSIS...JDW
NEAR TERM...REK
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...REK
MARINE...REK/JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
123 AM EDT THU MAY 7 2015
.SYNOPSIS...
LOW PRESSURE SOUTH OF CAPE FEAR MAY BECOME A SUBTROPICAL CYCLONE
OVER THE NEXT COUPLE OF DAYS. THE SYSTEM IS EXPECTED TO APPROACH
THE COAST OF SOUTH CAROLINA OR SOUTHERN NORTH CAROLINA FRIDAY AND
SATURDAY WITH INCREASING CHANCES FOR HEAVY RAIN...GUSTY WINDS...
AND DANGEROUS RIP CURRENTS AT THE BEACHES. UNSETTLED WEATHER
SHOULD PERSIST INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1:30 AM THURSDAY...BASED ON MOVEMENT OF PRECIP SHIELD AND
LATEST DATA HAVE SUBSTANTIALLY RAISED POPS FOR TODAY TO
CATEGORICAL FOR ALONG THE COAST. WILL ALSO LIKELY SPEED UP
WESTWARD PROGRESSION OF PRECIP FOR THE EARLY MORNING HOURS. FINAL
CUT FOR TODAYS RAIN EVENT NOT IN YET THOUGH...STILL TWEAKING
TIMING AND QPF AMOUNTS. DISCUSSION FROM 730 PM FOLLOWS...
THE LOW SEVERAL HUNDRED MILES SOUTH OF CAPE FEAR HAS CHANGED
LITTLE IN ORGANIZATION THIS AFTERNOON. THE LATEST WORD FROM THE
HURRICANE CENTER IS STILL FOR A 60 PERCENT CHANCE OF DEVELOPMENT
INTO A NAMED SUBTROPICAL STORM OVER THE NEXT FEW DAYS. THE NASA
GLOBAL PRECIPITATION MISSION (GPM) SATELLITE OVERFLEW THE SYSTEM
EARLY THIS AFTERNOON AND SHOWED RAINFALL ECHOES LARGELY DISLOCATED
FROM THE SATELLITE-INFERRED CIRCULATION CENTER. (SEE OUR LATEST
FACEBOOK/TWITTER POSTS) THIS DOES NOT BODE WELL FOR RAPID
STRENGTHENING...ALTHOUGH THIS COULD CHANGE AS THE SYSTEM REMAINS
NEAR THE WARM GULF STREAM CURRENT FOR AT LEAST ANOTHER 36 HOURS.
DENSE CIRRUS ALONG THE COAST SHOULD CONTINUE OVERNIGHT AS THE
UPPER LOW OFFSHORE MAINTAINS A SOUTHERLY FLOW AT 200-300 MB.
MOISTURE AT 700 MB IS REMAINING 50+ MILES OFFSHORE WITH RATHER DRY
AIR ACROSS THE EASTERN CAROLINAS AT THIS TIME. AS WINDS THROUGHOUT
THIS LEVEL TURN MORE EASTERLY TONIGHT THE LARGE SHIELD OF RAIN
VISIBLE ON THE PERIPHERY OF OUR RADAR SHOULD SHIFT
WESTWARD. I HAVE SLOWED DOWN THE WESTWARD ADVANCE OF
PRECIPITATION FROM PREVIOUS FORECASTS A BIT...WITH CHANCES OF
MEASURABLE RAIN BY DAYBREAK 30-50 PERCENT AT THE COAST AND 10
PERCENT OR LESS ALONG I-95. NO SIGNIFICANT CHANGES HAVE BEEN MADE
TO LOWS...STILL EXPECTED TO RANGE FROM THE UPPER 50S INLAND TO THE
LOWER 60S AT THE COAST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...A LARGE SWATCH OF SHOWERS AND THUNDERSTORMS
OFF THE FLORIDA EAST COAST AND IN THE VICINITY OF THE BAHAMAS HAS
BEEN RELUCTANT TO BECOME MUCH MORE ORGANIZED TODAY. THE NATIONAL
HURRICANE CENTER CONTINUES TO MONITOR AND MAY SEND A PLANE INTO
THE SYSTEM ON THURSDAY TO BETTER EVALUATE ITS STRUCTURE AND
INTENSITY. MODELS ARE RATHER CONSISTENT IN SHOWING A VERY SLOW
EVOLUTION AS THE SHOWERS AND THUNDERSTORMS CONTINUE TO ADVANCE/
EXPAND FURTHER NORTH ACROSS THE EASTERN CAROLINAS. HAVE INCLUDED
LIKELY TO WIDESPREAD CONVECTION FOR MUCH OF THE PERIOD. THE
PERSISTENCE OF THE RAINFALL MAY LEAD TO A RISK FOR SIGNIFICANT
PONDING AND PERHAPS SOME FLOODING. AT THIS TIME...IT IS DIFFICULT
TO PINPOINT WHERE THE HEAVIEST OF RAIN WILL FALL. CERTAINLY THERE
WILL BE PLENTY OF VERY HEAVY RAINFALL OFFSHORE. IF DEVELOPING LOW
PRESSURE IS ABLE TO DRIFT OR REDEVELOP WESTWARD AND CLOSER TO THE
COAST...THEN THE RISK FOR EXCESSIVE RAINFALL WILL MOVE ACROSS THE
EASTERN CAROLINAS. AT THIS TIME...RAINFALL AMOUNTS UP TO 1 TO 2
INCHES IS CERTAINLY POSSIBLE WITH AGAIN A POTENTIAL FOR MUCH
HIGHER AMOUNTS. THE COASTAL AREAS SHOULD BE PRONE TO THE HIGHER
RAINFALL TOTALS. OTHERWISE...GUSTY WINDS ARE EXPECTED WITH THE
STRONGEST WINDS NOW EXPECTED ON FRI...UP TO 20 TO 30 MPH AND FROM
THE NE. THE SURF ZONE WILL LIKELY BECOME DANGEROUS WITH BUILDING
BREAKERS...ROUGH SURF...STRONG RIP CURRENTS AND SIGNIFICANT BEACH
EROSION.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM WEDNESDAY...SYSTEM STILL SLOW TO ORGANIZE TODAY OFF THE
SOUTHEAST COAST. SO SLOW IN FACT THAT THE RECON HAS BEEN POSTPONED.
UNTIL THIS SYSTEM BEGINS TO CONGEAL (AT WHICH TIME AIRCRAFT RECON
WILL BECOME LIKELY) ITS STILL VERY TOUGH TO ASCERTAIN HOW THINGS
WILL PAN OUT. IN THE VERY NEAR TERM THE SOUTHERN CENTER JUST NORTH
OF THE BAHAMAS SEEMS TO BE WEAKENING IN FAVOR OF THE NORTHERN CENTER
ROUGHLY EAST OF JACKSONVILLE, FL. THE FORMER IS A WEAK REFLECTION OF
THE UPPER LOW WHILE THE LATTER IS THE MORE TYPICAL FRONTAL LOW. MOST
MODELS INDICATE THAT THE FRONTAL LOW REMAINS DOMINANT AND THAT THE
FRONTAL STRUCTURE WEAKENS AS THE SYSTEM MOVES SLOWLY TO THE NORTH.
THIS CONTINUES TO BE SUPPORTED BY THE FLORIDA STATE CYCLONE PHASE
DIAGRAMS THAT EVENTUALLY INDICATE A WEAKLY WARM CORE SYMMETRIC
SYSTEM. SSTS ARE MARGINAL TO SAY THE LEAST SO A HYBRID SYSTEM
APPEARS MORE LIKELY THAN PURELY TROPICAL BUT IN THE END NHC WILL
HAVE THAT CALL. LOCALLY THE CHANCE FOR HEAVY RAINFALL SEEMS TO BE
GOING UP MORE NOTABLY THAN THE CHANCE FOR ANY MEMORABLE WINDS.
ASSUMING AT LEAST SOME WARM RAIN PROCESSES THE TRACK OF THIS SYSTEM
(IT WILL BE A VERY SLOW MOVER AND MAY EVEN STALL, LOOP, OR
RETROGRADE) WE COULD SEE ANYTHING FROM A BENEFICIALLY VERY WET
WEEKEND TO SOME ARRANT FLOODING ISSUES. ANOTHER FACTOR THAT
COMPLICATES THE RAINFALL POTENTIAL IS THE SEEMING LIKELIHOOD OF A
HYBRID SYSTEM. THE RAINFALL DISTRIBUTION WILL NOT BE VERY SYMMETRICAL
ABOUT THE CIRCULATION. RATHER, THERE SHOULD BE A FOCUSED CHANNEL OF
SOUTHEASTERLY FLOW WHERE A FAIRLY LOCALIZED BULLSEYE OF HEAVY
RAINFALL IS FOCUSED. GIVEN THE AFOREMENTIONED POSSIBILITY OF A
STALLED OUT SYSTEM THE POP FORECAST WILL ONLY GRADUALLY DECREASE
HEADING INTO EARLY NEXT WEEK. MOISTURE FROM THIS SYSTEM COULD
CONCEIVABLY LINGER INTO TUESDAY OR WEDNESDAY AT WHICH TIME A COLD
FRONT WILL BE APPROACHING FROM THE NORTHWEST.
&&
.AVIATION /06Z WEDNESDAY THROUGH MONDAY/...
AS OF 06Z...CONFIDENCE IS STILL RATHER LOW...BUT IMPROVING AS THE
MODELS ARE STARTING TO GET A BIT MORE IN SYNC. LOW PRESSURE WILL
SLOWLY APPROACH THE REGION TOWARD MORNING...WITH SHOWERS AND MVFR
CONDITIONS EXPECTED AN HOUR OR TWO AFTER DAYBREAK ALONG THE COAST.
AGAIN...THE UNCERTAINTY IS THERE AS THE HRRR MODEL IS SLOWER THAN
THIS. THE GRADIENT WILL TIGHTEN ALSO AROUND DAYBREAK...WITH GUSTS
OVER 20 KTS A GOOD BET AFTER 14Z. THE INLAND TERMINALS WILL TAKE A
WHILE TO GET ANY PRECIP...PERHAPS BY MID AFTERNOON. THE COLUMN OF
DEEP MOISTURE WILL REMAIN OVER THE REGION THROUGH THE END OF THE
FORECAST PERIOD...WITH INTERMITTENT IFR POSSIBLE IN THE HEAVIER
PRECIP.
EXTENDED OUTLOOK...RAIN/MVFR. TEMPO IFR IN HEAVIER SHOWERS HIGHEST
CONFIDENCE COASTAL TERMINALS. BECOMING VFR/SHOWERS SUNDAY. VFR
ISOLATED SHOWERS MON.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1:30 PM THURSDAY...NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS:
LOW PRESSURE A FEW HUNDRED MILES SOUTH OF CAPE FEAR IS NOT
BECOMING APPRECIABLY BETTER ORGANIZED THIS EVENING...BUT CONTINUES
TO HAVE A BETTER THAN A 50-50 CHANCE OF BECOMING A NAMED
SUBTROPICAL CYCLONE IN THE NEXT FEW DAYS. REGARDLESS OF ITS
DESIGNATION...A LARGE COUNTERCLOCKWISE SWIRL OF WINDS FROM CAPE
HATTERAS INTO THE NORTHERN BAHAMAS IS BUILDING SEA HEIGHTS AT A
PRETTY GOOD RATE EARLY THIS EVENING. DATA FROM THE FRYING PAN
SHOALS BUOY INDICATES SEAS ARE ALREADY 7.2 FEET...WITH 4.5-5 FOOT
SEAS SHOWING UP VERY CLOSE TO SHORE AT THE TWO CORMP BUOYS NEAR
CAPE FEAR.
RADAR SHOWS RAIN OFFSHORE ON THE NORTHERN PERIPHERY OF THE CYCLONE
HAS PUSHED UP TO ABOUT 20 MILES FROM CAPE FEAR. RELATIVELY DRY
AIR SHOULD IMPEDE THIS RAIN FROM MOVING WESTWARD TOO RAPIDLY...BUT
SHOWERS SHOULD BE LIKELY ACROSS MOST OF THE WATERS BY DAYBREAK.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...SMALL CRAFT ADVISORY FLAGS WILL BE FLYING
THROUGH THE PERIOD. HOWEVER...THESE FLAGS MAY BE REPLACED BY A
TROPICAL STORM WATCH OR WARNING DURING/BY THURSDAY. IN EITHER
CASE...THE SLOW EVOLUTION AND MOVEMENT OF THIS SYSTEM UP THE
SOUTHEAST COAST AND ITS EXPANSIVE CONVECTION WILL CHURN UP SEAS
AND WE ARE EXPECTING SEAS TO BUILD UP TO 6 TO 10 FT...PERHAPS
PEAKING THU NIGHT AND FRI. WIND SPEEDS WILL BE UP TO 20 TO 30 KT
WITH HIGHER GUSTS AND THE DIRECTION WILL PRIMARILY BE FROM THE NE
AND E THU AND THU NIGHT AND E OR SE FRI AND FRI NIGHT.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 300 PM WEDNESDAY...WE WILL HAVE ADVISORIES UP ON SATURDAY
IF NOT TROPICAL WARNINGS FROM NHC. THE POSSIBLE SLOW AND ERRATIC
MOVEMENT OF THE SYSTEM WILL MAKE IT TOUGH TO SAY AT WHAT SPEED
CONDITIONS WILL IMPROVE AND AT WHAT TIME SUCH HEADLINES CAN BE
STEPPED DOWN. A STALLING OF THE STORM COULD ALSO MEAN THAT THE
WIND DIRECTION FORECAST IS OFF. IN THE END UNTIL THIS SYSTEM
STARTS TO CONGEAL INTO A MORE ORGANIZED AREA OF LOW PRESSURE
(TOMORROW OR FRIDAY) THERE IS JUST TOO MUCH UNCERTAINTY TO CHANGE
THE FORECAST MUCH AT ALL AT THIS TIME.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT FRIDAY FOR AMZ250-252-254-
256.
&&
$$
SYNOPSIS...RJD
NEAR TERM...REK/TRA
SHORT TERM...RJD
LONG TERM...MBB
AVIATION...DL
MARINE...REK/RJD/TRA/MBB
AREA FORECAST DISCUSSION
NWS BISMARCK ND
317 AM CDT THU MAY 7 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 317 AM CDT THU MAY 7 2015
FOCUS IN THE SHORT TERM WILL BE ON EXITING SHOWERS AND THE
POTENTIAL FOR FROST THURSDAY NIGHT.
THE LATEST 00 UTC SOLUTIONS OF THE ECMWF AND GFS ARE IN GOOD
AGREEMENT ON PROGRESSING THE UPPER LEVEL SHORTWAVE AND UPPER LEVEL
LOW NORTHEAST OUT OF NORTH DAKOTA SHORTLY AFTER 18 UTC THURSDAY.
BEHIND THE UPPER LEVEL LOW THE LATEST 05 UTC RUN OF THE HRRR SHOWS
SHOWERS ACROSS CENTRAL NORTH DAKOTA BECOMING SCATTERED BY 16 UTC.
FOR THIS REASON HAVE HASTENED THE EXIT OF PRECIPITATION ACROSS
WESTERN AND CENTRAL NORTH DAKOTA. ALSO WITH OBSERVATIONS SHOWING
NOTHING IN THE WAY OF THUNDERSTORMS IN THE VICINITY OF NORTH
DAKOTA HAVE WENT AHEAD AND REMOVED ALL CHANCES FOR THUNDERSTORMS
THROUGH TODAY.
LOOKING AT THE FROST POTENTIAL FOR THURSDAY NIGHT THE BEST CHANCES
FOR FROST WILL BE WEST AND NORTH CENTRAL. MOS GUIDANCE FROM THE
GFS IS SHOWING THE LOWER 30S ACROSS THE NORTHWEST WHILE THE NAM
GUIDANCE IS SUGGESTING THE UPPER 20S. MODEL BLENDS ALSO HAVE SOME
LOW CLOUDS BUILDING BACK INTO WESTERN AND CENTRAL NORTH DAKOTA
WITH SOME MID LEVEL CLOUDS ALREADY IN PLACE. FOR NOW HAVE OPTED TO
GO WITH A MODEL BLEND FOR LOWS THURSDAY NIGHT WHICH SUGGEST A
POTENTIAL FOR FROST DEVELOPMENT ACROSS THE WEST AND PORTIONS OF
NORTH CENTRAL NORTH DAKOTA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 317 AM CDT THU MAY 7 2015
PATTERN CONTINUES TO EXHIBIT COOLER THAN NORMAL TEMPERATURES THROUGH
TUESDAY AS A POCKET OF COLDER AIR/850 TEMPERATURES HOVER BETWEEN 0C
AND -2C ACROSS WESTERN AND CENTRAL NORTH DAKOTA. A COUPLE OF
HIGHLIGHTS TO NOTE...LOWS IN THE 30S WILL LIKELY LEAD TO FROST
AND/OR FREEZE HEADLINES DURING THE LATE NIGHT/EARLY MORNING HOURS
THROUGH TUESDAY MORNING. THE SECOND HIGHLIGHT IS IN REGARDS TO
PRECIPITATION. THE MAIN THREAT STILL LOOKS TO OCCUR OVER SOUTHERN
AND EASTERN NORTH DAKOTA OVER THE WEEKEND INTO EARLY NEXT WEEK...AND
WITH THE COLDER AIR ALOFT AND COOLING AT NIGHT...EXPECT SOME SNOW
SHOWERS AT TIMES.
FRIDAY THROUGH THROUGH MONDAY NIGHT...ON FRIDAY A SURFACE HIGH WILL
SHIFT FROM SOUTH CENTRAL SASKATCHEWAN INTO MANITOBA WITH A
DRY/NORTHEAST FLOW ACROSS WESTERN AND CENTRAL NORTH DAKOTA. HIGHS
WILL BE IN THE 50S. BY FRIDAY NIGHT ATTENTION TURNS TOWARD THE NEXT
CLOSED UPPER LOW OVER THE FOUR CORNERS/SOUTHWEST CONUS AS IT BEGINS
TO EJECT EAST TO NORTHEAST INTO THE CENTRAL HIGH PLAINS SUNDAY INTO
MONDAY. SOME PHASING OCCURS BETWEEN THE NORTHERN/SOUTHERN STREAM
TROUGHS DURING THIS TIME. THE HIGHEST POPS REMAIN FOCUSED ACROSS
SOUTHERN NORTH DAKOTA SATURDAY/SATURDAY NIGHT...THEN PIVOTING INTO
SOUTH CENTRAL AND THE JAMES RIVER VALLEY SUNDAY THROUGH MONDAY. AS
MENTIONED ABOVE EXPECT SOME CHANCES FOR SNOW MIXING IN WITH THE RAIN
AT NIGHT/EARLY MORNING WITH LITTLE OR NO ACCUMULATIONS.
MONDAY NIGHT THROUGH WEDNESDAY...DRY WEATHER SLATED FOR MONDAY NIGHT
INTO WEDNESDAY. THE SUPERBLEND BEGINS TO SHOW A GRADUAL WARMING TREND
INTO THE LOWER 60S WEDNESDAY...AS 850MB TEMPERATURES WARM TO BETWEEN
+3C AND +5C. HOWEVER BOTH THE GFS AND ECMWF KEEP A CYCLONIC FLOW/SOME
TROUGHING OVER NORTH DAKOTA THROUGH THE MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 317 AM CDT THU MAY 7 2015
LIGHT TO MODERATE SHOWERS WERE IMPACTING MOST ALL OF WESTERN AND
CENTRAL NORTH DAKOTA. THE FRONTAL BOUNDARY AS OF 06 UTC WAS JUST
EAST OF KBIS AND KMOT AND PROGRESSING SLOWLY EAST. THROUGH THE
MORNING HOURS IFR AND MVFR CONDITIONS WILL IMPACT ALL OF CENTRAL
AND WESTERN NORTH DAKOTA TERMINALS WITH IMPROVING CONDITIONS FROM
WEST TO EAST THROUGH THURSDAY AFTERNOON AND NIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...MM
LONG TERM...KS
AVIATION...MM
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
351 AM CDT THU MAY 7 2015
.SHORT TERM...
JUST AS WE SAW LAST NIGHT...STORMS MOVED OUT OF THE AREA OR WEAKENED
JUST AFTER MIDNIGHT LOCAL TIME AND THE DRYLINE CONTINUES TO SLOSH
BACK TO THE WEST. ONE DIFFERENCE IS THAT THERE IS A SUBTLE
SHORTWAVE OVER SOUTHEAST NEW MEXICO THAT IS TRYING TO GENERATE SOME
SHOWERS AS IT APPROACHES THE REGION. THIS SHORTWAVE MAY COMPLICATE
MATTERS FOR THIS AFTERNOON IF PRECIPITATION CAN DEVELOP AND BECOME
MORE EXPANSIVE ACROSS THE FORECAST AREA. THE RAP AND HRRR AND TO
SOME EXTENT THE NAM ARE TRYING TO DEVELOP AN AREA OF PRECIPITATION
ACROSS THE SOUTHWESTERN SOUTH PLAINS AND SOUTHEASTERN NEW MEXICO
THAT SPREADS NORTHEAST BEFORE SUNRISE. AMPLE LOW LEVEL MOISTURE
WILL BE IN PLACE TO THE EAST OF THE DRYLINE AS INDICATED BY LOW
CLOUDS AND PATCHY FOG ONCE AGAIN DEVELOPING ACROSS THE ROLLING
PLAINS AND STARTING TO SPREAD OVER THE CAPROCK. PULLED POPS BACK TO
THE WEST FOR THIS MORNING BUT KEPT THEM BARELY IN THE SLIGHT CHANCE
RANGE.
STORM CHANCES FOR THIS AFTERNOON WILL ONCE AGAIN DEPEND ON WHERE THE
DRYLINE MIXES TO AND IF ANY OTHER WEAK SHORTWAVES WILL MOVE ACROSS
THE AREA TO PROVIDE SOME WEAK LIFT TO INITIATE STORMS. FORECAST
SOUNDINGS STILL SHOW A BIT OF A WEAK CAP OVER THE AREA THIS MORNING
BUT THIS COULD EASILY BE OVERCOME BY DAYTIME HEATING. MLCAPE VALUES
WILL ONCE AGAIN CLIMB INTO THE 2000-3000 J/KG SO THERE WILL BE
PLENTY OF ENERGY FOR STORMS TO ACCESS. WIND PROFILES SHOW A BIT OF
A WEAKNESS BETWEEN 850 AND 700 HPA WHICH MAY IMPACT STORM MORPHOLOGY
BUT AMOUNT OF INSTABILITY AND DECENT VENTILATION ALOFT POINTS
TOWARDS THE POSSIBILITY OF SUPERCELLS WITH LARGE HAIL THE PREDOMINANT
THREAT. HOWEVER...RADAR LOOP SHOWS THAT THERE IS A POSSIBLE OUTFLOW
BOUNDARY FROM THE STORMS OVER OKLAHOMA/NORTH TEXAS THAT IS PUSHING
WEST. ADD IN BOUNDARIES LEFT OVER FROM ANY STORMS THAT MAY OR MAY
NOT DEVELOP THIS MORNING AND THERE COULD BE SOME LOCALIZED THREAT
FOR TORNADO DEVELOPMENT ALONG THESE BOUNDARIES. UNFORTUNATELY IT
IS TOO HARD TO TELL RIGHT NOW IF THERE WILL BE ANY ONE AREA OVER
ANOTHER THAT HAS A GREATER THREAT FOR TORNADOES.
TEMPERATURES WILL BE FAIRLY CLOSE TO WHAT WE SAW YESTERDAY FOR BOTH
MIN AND MAX TEMPS. AS MENTIONED EARLIER...DID INCREASE POPS THIS
MORNING AND ALSO INCREASED POPS ACROSS THE ROLLING PLAINS FOR THIS
AFTERNOON. PUT MENTION OF SEVERE IN FOR THE EASTERN TWO THIRDS OF
THE FORECAST AREA FOR THIS AFTERNOON AND EARLY EVENING BUT TAPERED
POPS OFF AFTER MIDNIGHT A BIT FOLLOWING THE DIURNAL CYCLE WE HAVE
SEEN THE LAST SEVERAL DAYS.
JORDAN
.LONG TERM...
LITTLE CHANGE TO THE EXTENDED FORECAST WITH THE PRIMARY FOCUS ON THE
ACTIVE EARLY MAY WEATHER THAT WILL PERSIST IN THE REGION INTO
SATURDAY.
THE UPPER LOW CURRENTLY DIGGING SOUTHWARD ACROSS THE WESTERN STATES
WILL BE CENTERED OVER SOUTHERN CA/NV TO KICK OF THE EXTENDED FRIDAY.
THERE IS GOOD AGREEMENT THAT THE LOW WILL MOVE STEADILY EASTWARD TO
NEAR THE FOUR CORNERS AROUND MIDDAY SATURDAY BEFORE EMERGING OVER
THE CENTRAL HIGH PLAINS ON SUNDAY. THIS TRACK WILL KEEP WEST TEXAS
UNDER STRENGTHENING SOUTHWESTERLY FLOW ALOFT WHILE RICH MOISTURE
ALREADY ENCOMPASSING MUCH OF THE LONE STAR STATE DOES NOT GO
ANYWHERE. VERY STEEP MID-LEVEL LAPSES ATOP THE RICH AND MOIST
BOUNDARY LAYER EAST OF THE DRYLINE WILL RESULT IN STRONG INSTABILITY
EVERY DAY...THOUGH ANY EARLY DAY CONVECTION AND CLOUD COVER WILL
DICTATE WHERE THE MOST VOLATILE AIR WILL RESIDE ON ANY PARTICULAR
AFTERNOON/EVENING. THE ABOVE FACTORS WILL WILL SET THE STAGE FOR
ROBUST MOIST CONVECTION ALONG AND EAST OF THE DRYLINE THE NEXT FEW
DAYS...WITH ALL FORMS OF SEVERE WEATHER /VERY LARGE HAIL...DAMAGING
WINDS AND ISOLATED TORNADOES/ POSSIBLE IN ADDITION TO LOCALLY HEAVY
RAIN.
CONVECTION COULD START FAIRLY EARLY ON FRIDAY AS ANOTHER SUBTLE
SHORTWAVE TROUGH IS PROGGED TO ROTATE AROUND THE UPPER LOW AND
APPROACH THE SOUTH PLAINS REGION BY MIDDAY OR SO. RECENT NWP SUGGEST
THE DRYLINE WILL BE POSITIONED SOMEWHERE NEAR THE EDGE OF THE
CAPROCK TOMORROW AFTERNOON...SO THE HIGHEST SEVERE WEATHER
PROBABILITIES WILL BE ALONG AND EAST OF THIS LINE FRIDAY
AFTERNOON/EVENING...THOUGH LOCATIONS FURTHER WEST COULD SEE
CONVECTION EARLY IN THE DAY. THE DRYLINE SHOULD QUICKLY RETREAT
FRIDAY NIGHT AS THE FLOW BACKS IN RESPONSE TO THE APPROACHING UPPER
LOW. IT APPEARS THE MOISTURE COULD MAKE IT ALL THE WAY BACK TO
THE TX/NM LINE FOR A SHORT TIME EARLY SATURDAY BEFORE
STRENGTHENING LOW-LEVEL SOUTHWESTERLY FLOW SHUNTS THE MOISTURE
BACK EASTWARD. ALTHOUGH NWP SIGNALS ARE MIXED...WE WOULD EXPECT
CONVECTION TO ERUPT ALONG THE DRYLINE EARLY SATURDAY AS THE
STRONGEST UPPER LIFT GRAZES THE AREA. THE DRYLINE AND EARLY DAY
CONVECTION SHOULD THEN RACE EASTWARD AS THE DRIER SOUTHWEST WINDS
SPREAD FROM WEST TO EAST ACROSS THE FA. THE DRYLINE MAY MAKE IT
ALL THE WAY TO OR EVEN SLIGHTLY EAST OF THE CWA BY SATURDAY
EVENING...THOUGH WE HAVE MAINTAINED SLIM POPS ACROSS THE FAR
EASTERN ZONES GIVEN THE UNCERTAINTY. WEST OF THE DRYLINE BREEZY TO
LOW-END WINDY CONDITION WILL ENVELOP THE CAPROCK SATURDAY
AFTERNOON WHILE TEMPERATURES PEAK NEAR EARLY MAY AVERAGES.
THE DRY WESTERLY FLOW WILL PERSIST OVER MUCH OF THE AREA SUNDAY WITH
MODEST COOLING AS THE UPPER TROUGH AXIS APPROACHES FROM THE WEST.
THE ONE EXCEPTION COULD BE THE FAR SOUTHEAST ZONES AROUND ASPERMONT
WHERE THE LOW-LEVEL MOISTURE MAY LINGER NEARBY AND PROVIDE AT LEAST
A LOW RISK OF A STORM.
A COLD FRONT WILL FOLLOW THE TROUGH PASSAGE EARLY MONDAY PROVIDING
BELOW AVERAGE TEMPERATURES AND DRY CONDITIONS TO BEGIN NEXT WEEK.
MOISTURE WILL GRADUALLY RETURN THEREAFTER AND WE COULD SEE THE UPPER
RIDGE EARLY IN THE WEEK BEGIN TO BREAKDOWN AND PROVIDE A RETURN OF
LOW THUNDER CHANCES TO THE FORECAST TOWARD MIDWEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 78 49 80 48 / 20 20 10 20
TULIA 79 54 81 54 / 30 20 30 40
PLAINVIEW 79 55 81 54 / 30 30 30 40
LEVELLAND 82 56 83 56 / 20 30 20 50
LUBBOCK 80 58 84 58 / 30 30 30 40
DENVER CITY 82 54 83 53 / 20 20 20 50
BROWNFIELD 83 56 85 57 / 30 30 30 50
CHILDRESS 82 61 84 64 / 50 40 50 40
SPUR 81 57 84 63 / 50 40 50 40
ASPERMONT 84 61 86 66 / 50 40 50 40
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
14/23
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
328 AM CDT THU MAY 7 2015
.SHORT TERM /NOW THROUGH FRIDAY/...H5 TROF WILL SLIDE SOUTHWARD
ACROSS CALIFORNIA AND INTO THE DESERT SOUTHWEST. MID LEVEL RIDGE
WILL BE DRAPED ACROSS THE WESTERN GULF OF MEXICO AND A S/W TROUGH
OFF THE FLORIDA COAST. PERSISTENT SOUTHEASTERLY FLOW WILL CONTINUE
WITH SFC HIGH PRESSURE ACROSS THE NORTHEASTERN GULF OF MEXICO AND
LOW PRESSURE ACROSS THE HIGH PLAINS. BREEZY CONDITIONS WILL
CONTINUE THROUGH THE SHORT TERM PERIOD WITH GUSTS TO 25-30 MPH
POSSIBLE IN THE AFTERNOON HOURS. 850-700MB TEMPERATURES WARM
THROUGH THE PERIOD SO AN INCREASE AN AFTERNOON HIGHS UP INTO THE
LOWER 90S MIDDLE/UPPER VALLEY WITH UPPER 80S IN THE LOWER VALLEY
EACH DAY.
FOR PRECIPITATION CHANCES...HAVE SLIGHT CHANCE POPS THIS MORNING FOR
ANY ISOLATED SHOWER THAT HAPPENS TO DEVELOP UNDERNEATH THE STRONG
INVERSION /MUCH LIKE THE PAST SEVERAL DAYS/. MODELS ONCE AGAIN
PROG A WEAK DISTURBANCE MOVING ACROSS THE HIGHER TERRAIN THIS
AFTERNOON AND EVENING. HRRR AND GFS DEVELOP THUNDERSTORMS OVER THE
SIERRA MADRES THIS AFTERNOON AND MOVE EAST TOWARDS THE UPPER
VALLEY. WILL MAINTAIN SLIGHT CHANCE POPS OUT WEST THIS EVENING
THEN DECREASE OVERNIGHT AS CIN INCREASES RAPIDLY.
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...THE APPROACH AND
PASSAGE OF A 500 MB TROUGH THROUGH THE TEXAS BIG BEND WILL ONCE
AGAIN INITIATE THUNDERSTORMS OVER THE NEIGHBORING HIGH TERRAIN OF
MEXICO...AND SOME OF THIS ACTIVITY MAY AFFECT THE BRO CWFA...
ESPECIALLY THE WESTERN THIRD AND NORTHERN HALF OF THE REGION.
STORM PREDICTION CENTER HAS A MARGINAL TO ENHANCED RISK OF SEVERE
WEATHER FOR MUCH OF TEXAS NORTH OF THE RIO GRANDE VALLEY AND DEEP
SOUTH TEXAS...SO SUCCESSIVE SHIFTS WILL HAVE TO MONITOR FOR THE
POSSIBILITY THAT SOME OF THIS STRONG TO SEVERE THUNDERSTORM
ACTIVITY MAY SNEAK INTO THE BRO CWFA FRIDAY NIGHT. AFTERWARDS...DRY
WEATHER WILL PREVAIL UNTIL ANOTHER POSSIBLE ROUND OF THUNDERSTORMS
OUT WEST SUNDAY NIGHT. A GREATLY ENHANCED OPPORTUNITY FOR RAINFALL
IS ANTICIPATED MONDAY THROUGH WEDNESDAY DUE TO THE INTRUSION AND
STALLING OF A WEAK COLD FRONT...A SOUTHWEST-TO-NORTHEAST 500 MB
FLOW OVERHEAD...AND THE FORMATION AND PERSISTENCE OF A SURFACE
TROUGH OF LOW PRESSURE WITHIN THE BRO CWFA. WITH DEEP TROPICAL
MOISTURE EXPECTED TO ALSO BE IN PLACE...WITH PRECIPITABLE WATER
VALUES AROUND 2 INCHES...THE POTENTIAL FOR LOCALLY HEAVY AND
FLOODING RAINFALL MAY EXIST MONDAY THROUGH WEDNESDAY. HOWEVER
...HAVE NOT INCLUDED THIS IN THE UPCOMING FORECAST AND WILL KEEP
AN EYE ON THE POTENTIAL FOR THIS HEAVY/FLOODING RAINFALL THROUGH
THE NEXT SEVERAL DAYS. NO MAJOR SURPRISES FOR THE TEMPERATURES...
NEAR TO SLIGHTLY ABOVE NORMAL THROUGHOUT THE ENTIRE LONG TERM
FORECAST PERIOD.
&&
.MARINE...NOW THROUGH FRIDAY...SEAS WERE NEAR 5 FEET WITH SOUTHEAST
WINDS NEAR 16 KNOTS AT BUOY020 THIS MORNING. MODERATE TO STRONG
SOUTHEAST WINDS WILL PREVAIL ACROSS THE COASTAL WATERS TODAY AS
THE PRESSURE GRADIENT REMAINS STRONG ACROSS THE WESTERN GULF OF
MEXICO. WILL HAVE SCEC ACROSS ALL LOWER TEXAS COASTAL WATERS TODAY
AND GULF WATERS TONIGHT. FOR FRIDAY SCEC WILL BE NEEDED ACROSS ALL
LOWER TEXAS COASTAL WATERS ONCE AGAIN.
FRIDAY NIGHT THROUGH WEDNESDAY...SURFACE HIGH PRESSURE CENTERED
JUST SOUTH OF THE FLORIDA PENINSULA WILL INTERACT WITH PERSISTENT
LOW PRESSURE OVER THE CENTRAL PLAINS FROM FRIDAY NIGHT THROUGH
THE WEEKEND...PRODUCING SMALL CRAFT ADVISORY WINDS/SEAS ALONG THE
LOWER TEXAS COAST THROUGH THIS PERIOD. ALTHOUGH HIGH PRESSURE WILL
BECOME MORE IN CONTROL OVER THE WESTERN GULF OF MEXICO AFTERWARDS
...ROUGH SWELLS FROM THE EAST-SOUTHEAST TO SOUTHEAST WILL CONTINUE
THE CHANCE FOR SMALL CRAFT ADVISORY MONDAY THROUGH WEDNESDAY...
ESPECIALLY FOR THE FAR OFFSHORE GULF OF MEXICO WATERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 86 77 87 78 / 10 10 10 20
BROWNSVILLE 87 77 88 76 / 20 10 10 20
HARLINGEN 90 77 90 76 / 20 10 10 20
MCALLEN 91 77 92 77 / 20 10 10 20
RIO GRANDE CITY 91 76 93 76 / 20 20 10 20
SOUTH PADRE ISLAND 82 76 82 78 / 10 10 10 20
&&
.BRO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
SHORT TERM...SCHOLL-55
LONG TERM...TOMASELLI-66
WX4PPT/MESO...BILLINGS-58
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
347 AM PDT Thu May 7 2015
.Synopsis...
A low pressure system dropping through northern California will
bring scattered showers or thunderstorms to much of Norcal today
then to the Sierra through the end of the week. Near normal
temperatures today then warming into the weekend. Breezy north
winds today mainly on the West side of the Valley. Chance of
showers or thunderstorms again early next week mainly northern
mountains.
&&
.Discussion (Today through Saturday)...
Upper level closed low has dropped southward into Northern
California this morning. Disturbances pivoting around the base of
the low are generating showers over Norcal south of line from about
Chester to Clear Lake and north of about Sacramento. The low is
forecast to continue southward into Socal later today and this
evening. Stability progs show slightly unstable conditions across
much of the CWA so can not rule out a threat of thunderstorms just
about anywhere in the forecast area especially this afternoon when
daytime surface heating maxes out for the day. Cool upper low will
bring down daytime highs today to near normal for this time of
year. Surface high pressure pushing in behind the upper low over
the Pacific Northwest has created a fairly tight surface gradient
across the north state and this is producing gusty north winds some
areas. Current MFR to SAC gradient is 12mb. Upper level support is
only weak however so the strongest winds are likely to be spotty
and fairly short lived. Decreasing gradients and winds are
expected by this afternoon. Upper low is progged to be over Socal
by late this afternoon. Therefore focus of heaviest precip
expected to be over the Sierra south of about Tahoe. Still looks
to be enough snowfall at pass levels to justify winter weather
advisory currently in place from highway 50 southward. Upper low
continues southeastward on Friday with RAP around moisture keeping
a threat of showers over the Sierra but allowing for warming
temperatures most other locations. Upper low moves eastward into
the eastern Great Basin on Saturday bringing clearing skies and
still warmer temperatures but a disturbance pivoting down the
backside of the low could bring a stray shower over the northern
Sierra Saturday afternoon. Models show an upper ridge over the west
coast late Saturday and early Sunday so most of the weekend should
be under fair skies with daytime highs pushing up to between 5 to
10 degrees above normal. A weak Pacific low is forecast by mid
range models to approach the coast late Sunday bringing a threat
of showers to the northwest corner of the state by late Sunday
afternoon or evening.
.Extended Discussion (Monday through Thursday)
Another upper low is forecast to dig south along the NW Cal coast
Monday. Models then differ significantly on how quickly to eject
the low by Wednesday. Potential for showers and thunderstorms
exist early next week, with Monday/Tuesday expected to be the most
active day. The GFS and GEM have more active weather with the low
over CA, while the EC tends to be drier and keeps the low offshore
of Oregon with only weak troughing over area. Cooling trend
expected with afternoon highs near to just below normal next week.
JClapp
&&
.Aviation...
Localized MVFR (bases 010 to 020) across area with showers and
t-storms today. Northerly sfc wind gusts to 30 kts today into
this evening. N-NE flight level 020 to 030 winds of 30-40 kts
late this aftn through evening as low moves south of area.
JClapp
&&
.STO Watches/Warnings/Advisories...
winter weather advisory until 5 am pdt friday west slope
northern sierra nevada.
&&
$$
AREA FORECAST DISCUSSION
NWS KEY WEST FL
1000 AM EDT THU MAY 7 2015
.DISCUSSION...IN THE MID AND UPPER LEVELS...(700-200 MB)...LATEST
AVAILABLE IR IMAGERY AS OF 700 AM OVERLAID WITH MODEL STREAMLINE
ANALYSIS DETAILS THE CONTINUED SPLIT FLOW AROUND A DOUBLE MID AND
UPPER LOW PRESSURE SYSTEM EXTENDING FROM OHIO SOUTH SOUTHEAST TO
EAST OF SAVANNAH...WITH 30 TO 40 KNOTS AROUND THE BASE OF THE BOTTOM
OF THE TROUGH. THIS MID AND UPPER SYSTEM EAST OF NORTH FLORIDA IS
DRAWING ACROSS LOTS OF MID AND UPPER DRY AIR AS VISIBLE ON THE
LATEST WATER VAPOR IMAGERY.
AT THE SURFACE AND IN THE LOWER TO MIDDLE LEVELS...SURFACE TO 700
MB...AS OF 900 AM...1010 MB SURFACE LOW PRESSURE DUE EAST OF
SAVANNAH GEORGIA IS CONTINUING TO INCREASE IN ORGANIZATION THIS
MORNING AND THE NATIONAL HURRICANE CENTER IS INDICATING THAT THE
SYSTEM HAS A 70 PERCENT CHANCE OF DEVELOPING INTO A SUBTROPICAL
CYCLONE THROUGH 48 HOURS. GIVEN THAT SYSTEM...AND NORMAL MID MORNING
HEATING TAKING PLACE OVER THE ISLANDS AND SOUTH FLORIDA AS A
RESULT...A LIGHT TO GENTLE NORTHEAST FLOW IS IN PLACE ACROSS THE
ISLANDS AND ADJOINING WATERS...BUT STRONG SUBSIDENCE IS PROHIBITING
ANY CLOUD FORMATION ALONG THE ISLAND CHAIN ATTM. THE 12Z MORNING
SOUNDING IS SOMEWHAT MOIST IN THE LOWER LEVELS...FROM THE SURFACE TO
700 MB...AND COLUMNAR PWAT AT 1.46 INCHES...BUT THE EAST FLOW IS
ONLY THROUGH 850 MB THEN BECOMES SOUTHWEST TO WEST WITHIN MIDDLE TO
UPPER LEVEL CYCLONIC FLOW.
.CURRENTLY...AS OF 900 AM...SKIES ARE SUNNY ACROSS THE ISLANDS AND
POINTS NORTHWARD...AND MOSTLY SUNNY ACROSS LOCATIONS OVER THE
STRAITS...WITH A FEW CELLS ALONG SOME BOUNDARIES IN THE OUTERMOST
FLORIDA STRAITS. TEMPERATURES HAVE RISEN TO AROUND 80 WITH SURFACE
DEWPOINTS A TAD HIGHER THAN 24 HOURS PRIOR...IN THE LOWER 70S ACROSS
THE ISLAND CHAIN. WINDS ARE LESS VARIABLE...BUT ALSO MORE
NORTHEASTERLY THAN YESTERDAY.
.SHORT TERM...MODEL FORECAST SOUNDINS VEER THE SURFACE TO 850 FLOW
MORE TO THE SOUTHEAST TODAY...BUT EVEN IF ENOUGH HEATING BACKS THE
LOWER LEVEL WINDS TO MORE NORTHEAST...THE DRIER AIR WITIH THE
AFOREMENTIONED DEEPER CYCLONIC CIRCULATION WILL BE RATHER PROHIBITIVE
IN THE FORMATION OF WELL DEVELOPED CLOUD LINES. SO WILL MAINTAIN A
DIME POP DUE TO POSSIBLE SPRINKLES OR A VERY LIGHT ISOLATED SHOWERS.
THESE LIGHTER EAST WINDS WILL LIMIT MIXING SO HIGH TEMPERATURES
REACHING THE MID 80S...LIKE YESTERDAY...SEEMS ON TRACK.
NONHYDROSTATIC WRF ALSO THE HRRR DO NOT DEVELOP LIGHT SHOWERS ALONG
MOST OF THE KEYS...BUT A SHOWER OR TWO MAY MOVE INTO THE UPPER KEYS
LATER IN THE AFTERNOON. THE ONGOING FORECAST IS ON TRACK AND NO
CHANGES ATTM.
&&
.MARINE...LIGHT TO GENTLE BREEZES GENERALLY FROM THE EAST WILL
PREVAIL OVER ALL FLORIDA KEYS WATERS THROUGH SATURDAY. AT
TIMES...WINDS MAY BECOME LIGHT AND VARIABLE. ISOLATED SHOWERS ARE
POSSIBLE...BUT THUNDERSTORMS ARE NOT EXPECTED AT THIS TIME THROUGH
SATURDAY.
&&
.AVIATION... VFR CONDITIONS WILL PREVAIL AT EYW AND MTH TODAY AND
TONIGHT. BRIEF...MVFR CEILINGS...BASED AT AROUND 2000 FEET...ARE
CONCEIVABLE AT EYW AND MTH LATE TONIGHT. THIS POSSIBILITY IS NOT
GREAT ENOUGH TO INCLUDE IN THE TERMINAL FORECASTS AT THIS TIME.
SUSTAINED EAST TO SOUTHEAST WINDS NEAR 10 KNOTS EXPECTED FROM JUST
OFF THE SURFACE TO ABOUT 3000 FEET.
&&
.CLIMATE... ON THIS DATE IN FLORIDA KEYS WEATHER HISTORY...IN
1937...4.08 INCHES OF RAIN FELL IN KEY WEST. THIS SET THE DAILY
RECORD FOR MAXIMUM RAINFALL MEASURED IN KEY WEST ON MAY 7TH...A
RECORD WHICH STILL STANDS 78 YEARS LATER. RAINFALL RECORDS AT KEY
WEST DATE BACK TO 1871.
&&
.KEY WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GM...NONE.
&&
$$
PUBLIC/MARINE.........DAF
AVIATION/CLIMATE.....BS
DATA COLLECTION......SC
VISIT US ON THE WEB AT WEATHER.GOV/KEY
FOLLOW US ON FACEBOOK AND TWITTER AT...
WWW.FACEBOOK.COM/NWSKEYWEST
WWW.TWITTER.COM/NWSKEYWEST
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1051 AM EDT THU MAY 7 2015
.SYNOPSIS...
LOW PRESSURE OFF THE GEORGIA AND SOUTH CAROLINA COAST WILL SLOWLY
MOVE NORTH TODAY THEN TO COASTAL SOUTH CAROLINA FRIDAY. THE LOW
WILL STALL OFFSHORE OF SC THROUGH SATURDAY WITH CHANCES OF SHOWERS
AND THUNDERSTORMS CONTINUING. A COLD FRONT WILL CROSS THE AREA
EARLY NEXT WEEK WITH CHANCES OF SHOWERS AND THUNDERSTORMS
REMAINING IN THE FORECAST.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOW PRESSURE OFFSHORE SOUTH CAROLINA MOVING VERY SLOWLY TO THE
NORTH. MOISTURE FLUX TRANSPORT FOCUSED ACROSS THE NORTH COASTAL
REGION SOUTH CAROLINA. AIR MASS ACROSS MIDLANDS REMAINS FAIRLY DRY
WITH LOW WITH PRECIPITABLE WATER BELOW 1.00 INCH.
HOWEVER...LATEST RADAR TRENDS SUGGEST SHOWERS ARE MOVING WEST INTO
EAST CENTRAL MIDLANDS. LATEST HRRR MODEL SUGGEST A BAND OR TWO OF
SHOWERS MAY SPREAD WEST INTO COLUMBIA BY EARLY AFTERNOON.
THEREFORE...RAISED POPS TO CHANCE CENTRAL AND LIKELY EAST THROUGH
AFTERNOON. TEMPERATURES WILL BE TRICKY ONCE AGAIN THIS AFTERNOON
DEPENDING ON CLOUD COVER AND CHANCES FOR SHOWERS. TEMPERATURES
MAY STRUGGLE TO RISE EAST OF COLUMBIA.GUIDANCE AND LOCAL NUMBERS
RANGING FROM THE MIDDLE 70S ACROSS THE EAST TO MIDDLE 80S ACROSS
THE CSRA. HAVE CONTINUED WITH THIS TREND OF LOWER TEMPERATURES
ACROSS THE EASTERN MIDLANDS WITH MID/UPPER 70S AND WARMEST
TEMPERATURES ACROSS THE CSRA WITH LOWER 80S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
TONIGHT THE LOW WILL MOVE SLOWLY NORTHWARD AND THEN STALL OFFSHORE
OF MYRTLE BEACH BY FRIDAY INTO FRIDAY NIGHT. THE MODELS HAVE
CONTINUED WITH THEIR TREND OF THIS SLOW NORTHWARD MOVEMENT AND
STALL ALONG THE SC COAST. THIS WILL CONTINUE TO SPREAD PLENTY OF
MOISTURE INTO THE FORECAST AREA. THE LOW IS EXPECTED TO
STRENGTHEN AS IT MOVES NORTHWARD AS IT WILL BE OVER THE GULF
STREAM WITH SEA SURFACE TEMPERATURES IN THE UPPER 70S. NATIONAL
HURRICANE CENTER CONTINUES TO MONITOR THIS SYSTEM AND CURRENTLY
FORECASTS A 70 PERCENT CHANCE OF DEVELOPING INTO A TROPICAL
SYSTEM. ALTHOUGH THERE WILL BE SOME WIND AND TIDAL CONCERNS ALONG
THE COAST THE MAIN CONCERN FOR THE MIDLANDS AND CSRA WILL BE
POTENTIAL FOR RAIN. DEPENDING ON THE EXACT TRACK OF THE
SYSTEM...SOME PORTIONS OF THE EASTERN MIDLANDS/PEE DEE COULD SEE
SOME LOCALLY HEAVY RAIN. HEAVIEST RAINFALL WILL BE ACROSS THE
EASTERN MIDLANDS WITH UP TO ONE HALF INCH POSSIBLE THROUGH
FRIDAY...WITH AROUND ONE TENTH OF AN INCH FOR THE MIDLANDS.
CONCERN WITH RAINFALL WILL BE BREAKS IN THE CLOUDS ALLOWING FOR
HEATING AND DEVELOPMENT OF THUNDERSTORMS...WHICH WOULD CHANGE THE
ACCUMULATIONS GREATLY. HIGH TEMPERATURES WILL BE IN THE UPPER 70S
TO LOWER 80S IN THE EASTERN MIDLANDS WITH LOWER TO MIDDLE 80S
ELSEWHERE AND OVERNIGHT LOWS IN THE LOWER TO MIDDLE 60S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
MODELS HAVE COME INTO BETTER AGREEMENT WITH THE COASTAL LOW
LINGERING WITH A COLD FRONT CROSSING THE REGION EARLY NEXT WEEK.
COASTAL LOW WILL REMAIN QUASI-STATIONARY OFFSHORE OF SC SATURDAY
THEN BEGIN SLOWLY EJECTING NORTHWARD SUNDAY THROUGH MONDAY. THE
GFS REMAINS THE SLOWEST EJECTING THE LOW SO HAVE TRENDED THE
SATURDAY THROUGH SUNDAY TIME FRAME TOWARD THE ECMWF. PLENTY OF
MOISTURE WILL LINGER INTO NEXT WEEK WITH A COLD FRONT CROSSING THE
LOWER MS VALLEY MONDAY AND MOVING INTO THE FORECAST AREA TUESDAY.
THIS WILL KEEP CHANCES OF SHOWERS AND THUNDERSTORMS IN THE
FORECAST WITH HIGH PRESSURE TRYING TO PUSH DRIER AIR INTO THE
REGION FOR WEDNESDAY. GFS AND ECMWF DIFFER ON HOW FAST AND FAR
SOUTH/EAST THE FRONT WILL PUSH. ECMWF HINTS AT THE FRONT BECOMING
STATIONARY ACROSS THE AREA. CONCERN FOR SATURDAY AND SUNDAY WILL
BE POSITION AND PROGRESSION OF THE COASTAL LOW. WITH BREAKS IN THE
CLOUDS AND DIURNAL HEATING THUNDERSTORMS WILL BE POSSIBLE AND THE
POTENTIAL FOR LOCALLY HEAVY RAIN...MAINLY OVER THE EASTERN
MIDLANDS...WILL CONTINUE. WILL CONTINUE TO MONITOR AND ADJUST
RAINFALL AMOUNTS AS CONFIDENCE INCREASES IN MODELS. TEMPERATURES
THROUGH THE LONG TERM WILL BE NEAR TO SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
VFR FORECAST.
AN AREA OF LOW PRESSURE OFF THE GEORGIA COAST WILL CONTINUE TO DRIFT
NORTHWARD THROUGH FRIDAY. MID AND HIGH LEVEL CLOUDS ASSOCIATED WITH
THIS DISTURBANCE WILL AFFECT THE TAF SITES TODAY. CANNOT RULE OUT
SCATTERED SHOWERS MAINLY NEAR OGB TERMINAL AFTER 18Z...BUT LIKELY
NOT TO RESULT IN RESTRICTIONS. GUIDANCE ALSO INDICATING THAT SOME
STRONGER WINDS COULD DEVELOP AFTER 16Z WITH GUSTS AROUND 20 KNOTS.
LOW CLOUDS COULD BEGIN MOVING INTO THE MIDLANDS TAF SITES BEFORE
DAWN FRIDAY MORNING...THOUGH CONFIDENCE IS TOO LOW TO MENTION
RESTRICTIONS ATTM.
EXTENDED AVIATION OUTLOOK...MODELS INDICATE THE SURFACE LOW
REMAINING OFF THE COAST SC AND TAKING IT TOWARD THE OUTER BANKS OF
NC FOR THE WEEKEND. COULD SEE INTERMITTENT RESTRICTIONS FRIDAY
THROUGH MONDAY. SCATTERED CONVECTION POSSIBLE...ESPECIALLY FROM CAE
AND OGB ON EASTWARD.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
77
AREA FORECAST DISCUSSION
NWS BOISE ID
959 AM MDT THU MAY 7 2015
.DISCUSSION...PRECIPITATION SHIELD SOUTH OF A LINE FROM KUNA
THROUGH MOUNTAIN HOME TO JEROME AT 940 AM WILL LIFT SLOWLY NORTH
TODAY ACROSS CENTRAL IDAHO. UNDER THIS AREA STEERING WINDS ARE
LIGHT /NE TO SE 15 MPH/ AND HIGH TEMPERATURES WILL BE COOL /UPPER
40S AND 50S/. SO...STABILITY PARAMETERS AND LATEST HRRR RUNS DO
NOT SUPPORT THUNDERSTORMS THERE. THUNDERSTORMS ALREADY IN EASTERN
NV IN THE EAST FLANK OF THE UPPER LOW ARE ASSOCIATED WITH AN UPPER
IMPULSE SEEN ON WATER VAPOR IMAGERY AND SURFACE LOW. THE UPPER
IMPULSE IS EXPECTED TO PIVOT AROUND THE LOW AND BRING A SMALL
THREAT OF THUNDERSTORMS TO THE WEST MAGIC VALLEY AND AREAS SOUTH
AND WEST TO THE ID-NV BORDER...UNTIL AROUND 02Z OR 8 PM MDT. MINOR
UPDATES REFINE THUNDERSTORM AREA IN THE SHORT TERM. REMAINDER OF
THE FORECAST THROUGH THIS WEEKEND IS ON TRACK WITH...UNSETTLED
WEATHER MAINLY OVER IDAHO THROUGH FRIDAY EVENING AND DRY WEATHER
EVEN IN THE MOUNTAINS BY SUNDAY....IS ON TRACK.
&&
.AVIATION...VFR. BROKEN TO OVERCAST MID LEVEL CLOUDS WITH ISOLATED
SHOWERS OVER SOUTHWEST IDAHO. SHOWER COVERAGE WILL INCREASE TO
SCATTERED THIS AFTERNOON...MAINLY ACROSS SOUTHWEST IDAHO. ISOLATED
THUNDERSTORMS DEVELOPING LATE THIS AFTERNOON ALONG THE NEVADA
BORDER. SURFACE WINDS NORTHWESTERLY 10-15 KNOTS WITH GUSTS TO 20
KTS. WINDS ALOFT NORTHWESTERLY AROUND 10 KNOTS UP THROUGH 10K FEET
MSL.
&&
.PREV DISCUSSION...
SHORT TERM...TODAY THROUGH FRIDAY...MODELS CONTINUE TO HAVE GOOD
OVERALL CONSISTENCY IN THE SHORT TERM WITH THE LARGE-SCALE FLOW
AND EVEN SOME SURFACE FEATURES...BUT THE QPF FIELDS ARE CHANGING
DRAMATICALLY FROM RUN TO RUN AND DIFFER GREATLY BETWEEN MODELS. WE
PUT A GREAT DEAL OF WEIGHT ON THE SREF OUTPUT FOR THIS PACKAGE BUT
STILL RETAINED SOME OF THE DETERMINISTIC MODEL OUTPUT TO TRY TO
MAINTAIN SOME HIGHER AMOUNTS IN THE FORECAST. HOWEVER...CONFIDENCE
IN LOCATION OF MAX PRECIP OVER THE NEXT 36 HOURS IS WELL BELOW
NORMAL. THERE IS STILL NOTABLE CONVECTIVE POTENTIAL IN THE SE
PORTION OF THE CWA THIS AFTERNOON AND EVENING...AND AGAIN
TOMORROW. THE ONE CHANGE WAS TO PUT A SLIGHT CHANCE OF
THUNDERSTORMS BACK INTO THE TREASURE VALLEY AS WE EXPECT SOME
STORMS TO ADVECT OFF THE MOUNTAINS IN THE EASTERLY FLOW. ALSO...
WITH DEWPOINTS RISING THIS MORNING...THERE SEEMS TO BE ENOUGH OF A
THREAT TO WARRANT A MENTION. THERE WERE LARGE DISCREPANCIES IN THE
TEMP FORECASTS FROM THE GFS TO NAM FOR TODAY/S HIGHS THIS TIME
YDAY...BUT THEY HAVE LARGELY COME TO THE CENTER IN THE LATEST
RUNS. THIS IS WHERE OUR FORECAST HAS BEEN FOR SEVERAL DAYS
NOW...SO THERE WAS VIRTUALLY NO CHANGE IN THE TEMP FORECAST. WE
WILL SEE A SLOW WARMING TREND ON FRIDAY AS THE UPPER LOW MOVES
AWAY FROM THE AREA AND HEIGHTS RISE. THUNDERSTORMS WILL AGAIN BE
IN THE FORECAST FRIDAY AFTERNOON FOR THE SOUTHEAST PORTION OF THE
CWA. WINDS WILL NOT BE STRONG IN THE SHORT TERM...BUT WILL BLOW
NEAR 20 MPH IN SE OREGON THIS AFTERNOON...AND AS ALMOST ALWAYS
WILL BE GUSTY NEAR STORMS OR SHOWERS THAT FORM.
LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY...MODELS IN RELATIVELY
GOOD AGREEMENT OVER THE WEEKEND WITH TIMING AND PLACEMENT DIFFERENCE
SHOWING UP OVER THE REGION BY EARLY NEXT WEEK. THE ONE CONSISTENT
THING WITH THE MODELS IS THAT THE PATTERN WILL REMAIN ACTIVE.
UPPER LEVEL LOW CENTERED OVER SOUTHERN NEVADA FRIDAY NIGHT WILL
MOVE EAST TO THE FOUR CORNERS AREA AND WEAKEN WITH A BROAD OPEN
TROUGH OVER THE FOUR CORNER STATES BY SATURDAY AFTERNOON. AS THIS
LOW MOVES EAST PRECIPITATION OVER THE FORECAST AREA WILL DECREASE
FROM WEST TO EAST WITH SLIGHT CHANCE POPS OVER EASTERN ZONES OF
SOUTHWEST IDAHO. SATURDAY NIGHT AND SUNDAY THE LOW WILL CONTINUE
TO WEAKEN AND MOVE TO THE NORTHEAST AS AN UPPER LEVEL RIDGE BUILDS
OVER THE INTERMOUNTAIN REGION. THIS RIDGE WILL BRING MOSTLY DRY
CONDITIONS TO THE FORECAST AREA. SUNDAY NIGHT INTO MONDAY MODELS
BEGIN TO DIVERGE ON TIMING AND PLACEMENT OF THE NEXT UPPER LEVEL
TROUGH AND ASSOCIATED LOW THAT WILL BE MOVING INTO THE WEST COAST.
LATEST GFS CONTINUES TO DIG THE LOW SOUTH ALONG THE COAST BUT THE
NEWEST ECMWF NOW HOLD THE LOW OFF THE WASHINGTON COAST WITH LITTLE
CHANGE IN EITHER MODEL FROM MONDAY THROUGH TUESDAY. WITH THE
DIFFERENCES BETWEEN THE MODELS OF THE PLACEMENT OF THE LOW ALSO
MEANS DIFFERENCES IN WHERE PRECIPITATION WILL FALL. WILL LITTLE
CONFIDENCE IN THE MODELS THAT FAR OUT DECIDED TO GO TOWARDS A
MODEL BLEND. WEDNESDAY GFS HAS THE LOW OVER SOUTHERN CALIFORNIA/
SOUTHERN NEVADA WHILE THE ECMWF SHIFTS THE LOW WEST OFF THE
COAST. WITH LOW CONFIDENCE IN THE MODELS WILL CONTINUE WITH A
MODEL BLEND. TEMPERATURES THROUGH THE EXTENDED WILL AVERAGE A FEW
DEGREES ABOVE NORMAL.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
OR...NONE.
&&
$$
WEATHER.GOV/BOISE
DISCUSSION...VM
AVIATION.....JS
PREV SHORT TERM...SP
PREV LONG TERM....JA
AREA FORECAST DISCUSSION
NWS DULUTH MN
1016 AM CDT THU MAY 7 2015
.UPDATE...
ISSUED AT 1014 AM CDT THU MAY 7 2015
WE HAVE MADE SOME ADJUSTMENTS THIS MORNING TO LOWER POPS...MAINLY
FAR EAST WHERE NO RAIN HAS FALLEN YET. OVERALL...AREA RADARS SHOW
SCATTERED SHOWERS WITH HIGHEST COVERAGE OVER OUR NORTHWEST ZONES
AS OF 15Z. SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS AFTERNOON
BUT COVERAGE MAY NOT BE WIDESPREAD. WE LEFT POPS HIGH THOUGH AS WE
DO EXPECT TO SEE SHOWERS AND STORMS MOVE THROUGH...BUT THERE WILL
BE BREAKS AT TIMES.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 355 AM CDT THU MAY 7 2015
AT 345 AM...WE SAW ONE AREA OF SHOWERS EXITING THE INTERNATIONAL
BORDER REGION...WHILE A NEW AREA OF SHOWERS AND POSSIBLE STORMS
WAS MOVING INTO THE SOUTHERN CWA. AN AREA OF PARTIAL CLEARING HAD
DEVELOPED IN BETWEEN THOSE TWO AREAS OF PRECIPITATION.
TEMPERATURES RANGED FROM THE 40S NEAR LAKE SUPERIOR TO THE LOWER
60S IN THE SOUTHERN PORTION OF THE CWA.
THE FOCUS FOR THE PERIOD FROM TODAY THROUGH FRIDAY...AND ESPECIALLY
FOR TODAY...IS TRYING TO RESOLVE THE OVERALL PRECIPITATION POTENTIAL
AND AMOUNTS. AN ANALYSIS OF THE HRRR/RAP/WRF AND THE NAM/GFS/ECMWF
INDICATED NONE OF THE MODELS HAD A GOOD HANDLE ON THE CURRENT
PRECIPITATION AREA...WITH MOST OF THE MODELS TOO SLOW WITH THE
CURRENT SHOWERS MOVING INTO THE SOUTHERN CWA. OVERALL...THINK THE
MODELS DO CATCH UP AND THE TREND FOR INCREASING PRECIPITATION
TODAY SOUNDS LIKE A REASONABLE SCENARIO. WILL GENERALLY HAVE HIGH
POPS ACROSS THE CWA TODAY AND TONIGHT...WITH CHANCES INCREASING
THROUGHOUT THE MORNING TODAY. HIGH RESOLUTION MODELS SUCH AS THE
4KM NMM WRF AND THE HRRR INDICATE THE MODE OF PRECIPITATION SHOULD
BECOME MORE CELLULAR DURING THE DAY. SPC HAS A PORTION OF OUR AREA
IN THE MARGINAL SEVERE WEATHER THREAT AREA...AND THAT SEEMS
REASONABLE GIVEN THE BETTER CHANCE FOR SEEING SOME DAYTIME HEATING
AND PARTIAL SUNSHINE IN THE SOUTHERN PORTION OF THE CWA.
PRECIPITABLE WATER VALUES THIS MORNING ARE GENERALLY IN THE 1.2
INCH RANGE. A FORMIDABLE LLJ OF UP TO 50 KT WAS EVIDENT THROUGHOUT
THE PLAINS AND UPPER MIDWEST.
TODAY...WILL GO WITH FAIRLY HIGH POPS. PRECIPITATION WILL COME IN
WAVES AND INCREASE THROUGHOUT THE DAY. HIGHS SHOULD GENERALLY BE
IN THE 70S...ALTHOUGH SOME 60S ARE POSSIBLE IN SPOTS...WITH 40S
AND 50S NEAR THE LAKE. COULD BE SOME STRONG THUNDERSTORMS DURING
THE LATTER PORTION OF THE DAY...AND POSSIBLY AN ISOLATED SEVERE
THUNDERSTORM ACROSS THE SOUTHEAST HALF OF THE CWA.
TONIGHT...SHOWERS AND THUNDERSTORMS WILL BE LIKELY. A FEW STRONG
STORMS WILL AGAIN BE POSSIBLE DURING THE EVENING...ESPECIALLY
ACROSS THE SOUTHEASTERN PORTION OF THE CWA. BY 06Z FRIDAY...THE
COLD FRONT SHOULD REACH THE DULUTH AREA...AND IT SHOULD JUST ABOUT
CLEAR THE SOUTHEAST CWA BY 12Z FRIDAY. WINDS WILL SWITCH TO THE
NORTHWEST BEHIND THE FRONT.
FRIDAY...THE SHOWERS AND STORMS WILL GRADUALLY DIMINISH FROM THE
WEST. ONLY A FEW SHOWERS WILL LINGER FAR EAST INTO THE AFTERNOON.
DRIER AIR WILL PUSH IN FROM THE NORTHWEST...AS DRIER AND COOLER
AIR SPREADS INTO THE AREA FROM CANADIAN HIGH PRESSURE. HIGHS WILL
BE IN THE 50S FOR MOST OF NE MN...WITH SOME 60S IN WI.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU MAY 7 2015
HIGH PRESSURE AT THE SURFACE WILL BE BUILDING IN ACROSS SRN MANITOBA
AND WRN ONTARIO FRIDAY NIGHT AND SATURDAY...AND INTO LAKE SUPERIOR
SAT NIGHT. AS THE HIGH SHIFTS SLIGHTLY TO THE EAST THE NEXT
SIGNIFICANT LOW PRESSURE SYSTEM WILL MOVE FROM THE SRN PLAINS INTO
THE UPPER MIDWEST BY LATE SUNDAY NIGHT/MON MORNING. THE COMBINATION
OF THE SFC HIGH AND APPROACHING LOW TO THE SOUTH WILL INDUCE A
PERSISTENT E/NE WIND OFF LAKE SUPERIOR FRI NIGHT THROUGH MONDAY
NIGHT. THE APPROACHING SYSTEM WILL ONCE AGAIN DRAW UP A LARGE SUPPLY
OF MOISTURE FROM THE SOUTH AND DEPOSIT IT IN THE FORM OF WIDESPREAD
RAIN SHOWERS ACROSS THE NORTHLAND THROUGH THE DAY SUNDAY AND
CONTINUING INTO MONDAY AS THE SYSTEM WRAPS UP MOVING INTO THE GREAT
LAKES. THIS SYSTEM WILL BE FAIRLY DYNAMIC WITH A STRONG WARM FRONT
OUT AHEAD OF THE LOW...WHICH COULD BE CAPABLE OF PRODUCING SCATTERED
THUNDERSTORMS WITH THE SHOWERS DURING THE DAY SUNDAY. THE SYSTEM
THEN BEGINS TO LOOK MORE LIKE A WINTER-TYPE LOW AS AN AREA OF COLDER
AIR FILLS IN ON THE BACK SIDE...AND A TROWAL-LOOKING FEATURE
DEVELOPS TO THE EAST WITH AN AREA OF ROBUST STRATIFORM RAIN FORMING
IN THE DEFORMATION ZONE ACROSS NRN MN. THE RAIN SHOULD LINGER INTO
LATE MONDAY AND EARLY TUESDAY AS THE COLD AIR CONTINUES TO DROP IN
ACROSS THE UPPER MIDWEST BEHIND THE DEPARTING SYSTEM. THE AMT AND
DEPTH OF THE COLD AIR COULD ACTUALLY CHANGE OVER TO RAIN OR MIX WITH
SNOW AT TIMES TUESDAY MORNING. NO ACCUMULATION IS EXPECTED AT THIS
TIME. HIGH PRESSURE WILL BUILD IN BEHIND THE SYSTEM INTO THE MIDDLE
OF THE WEEK...BUT ONLY FOR A BRIEF PERIOD AS THE NEXT WEAK INVERTED
TROUGH SLIDES IN FROM THE WEST WITH ADDITIONAL CHANCES FOR LIGHT
RAIN.
TEMPERATURES WILL BE NOTICEABLY COOLER THROUGH MUCH OF THE EXTENDED
PERIOD...ESPECIALLY AROUND THE TWIN PORTS AREA WITH A PERSISTENT
E/NE WIND OFF LAKE SUPERIOR. WHILE AREAS INLAND COULD SEE UPPER 50S
AND 60S AT TIMES...LOCATIONS CLOSER TO THE LAKE WILL ONLY SEE 40S
AND LOWER 50S DURING THE DAY. THE PRESENCE OF A LAKE BREEZE WILL
MAKE IT SEEM EVEN COLDER. OVERNIGHT LOWS WILL GENERALLY BOTTOM OUT
IN THE 30S AND LOWER 40S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 637 AM CDT THU MAY 7 2015
RAIN SHOWERS WILL CONTINUE TO MOVE NWD THROUGH THE REGION ALONG
AND AHEAD OF A SLOW MOVING N-S ORIENTED COLD FRONT. WILL LIKELY
SEE THE INITIAL BAND OF SHOWERS MOVE THROUGH THIS MORNING WITH
POSSIBLY A BRIEF BREAK IN THE LATE MORNING AND EARLY AFTERNOON.
SLIGHT DESTABILIZATION IN THE AFTERNOON WILL LEAD TO POSSIBLY A
ROUND OF MORE INTENSE RAIN SHOWERS AND SCATTERED THUNDERSTORMS.
THE SHOWERS AND STORMS COULD LINGER INTO THE EVENING BEFORE
TAPERING OFF AND/OR BECOMING MORE LIGHT AND STRATIFORM INTO THE
LATE EVENING AND OVERNIGHT. THE FRONT WILL PUSH THROUGH LATE
TONIGHT AND FRIDAY MORNING WITH LOW CLOUDS AND RAIN LINGERING.
SHOULD SEE IMPROVEMENT IN CONDITIONS FROM NW TO SE FRI MORNING.
EXPECT GUSTY SOUTH WINDS AHEAD OF THE FRONT TODAY...WITH A SHIFT
TO LIGHT AND VARIABLE NEAR THE FRONT AND VEERING WINDS TO THE NW
BEHIND THE FRONT TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 69 47 58 40 / 80 80 20 0
INL 68 42 53 34 / 80 70 20 0
BRD 70 47 57 39 / 80 70 10 0
HYR 76 53 63 41 / 80 80 20 0
ASX 79 52 62 37 / 70 80 30 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...MELDE
SHORT TERM...DAP
LONG TERM...BJT
AVIATION...BJT
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
638 AM CDT THU MAY 7 2015
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 355 AM CDT THU MAY 7 2015
AT 345 AM...WE SAW ONE AREA OF SHOWERS EXITING THE INTERNATIONAL
BORDER REGION...WHILE A NEW AREA OF SHOWERS AND POSSIBLE STORMS
WAS MOVING INTO THE SOUTHERN CWA. AN AREA OF PARTIAL CLEARING HAD
DEVELOPED IN BETWEEN THOSE TWO AREAS OF PRECIPITATION.
TEMPERATURES RANGED FROM THE 40S NEAR LAKE SUPERIOR TO THE LOWER
60S IN THE SOUTHERN PORTION OF THE CWA.
THE FOCUS FOR THE PERIOD FROM TODAY THROUGH FRIDAY...AND ESPECIALLY
FOR TODAY...IS TRYING TO RESOLVE THE OVERALL PRECIPITATION POTENTIAL
AND AMOUNTS. AN ANALYSIS OF THE HRRR/RAP/WRF AND THE NAM/GFS/ECMWF
INDICATED NONE OF THE MODELS HAD A GOOD HANDLE ON THE CURRENT
PRECIPITATION AREA...WITH MOST OF THE MODELS TOO SLOW WITH THE
CURRENT SHOWERS MOVING INTO THE SOUTHERN CWA. OVERALL...THINK THE
MODELS DO CATCH UP AND THE TREND FOR INCREASING PRECIPITATION
TODAY SOUNDS LIKE A REASONABLE SCENARIO. WILL GENERALLY HAVE HIGH
POPS ACROSS THE CWA TODAY AND TONIGHT...WITH CHANCES INCREASING
THROUGHOUT THE MORNING TODAY. HIGH RESOLUTION MODELS SUCH AS THE
4KM NMM WRF AND THE HRRR INDICATE THE MODE OF PRECIPITATION SHOULD
BECOME MORE CELLULAR DURING THE DAY. SPC HAS A PORTION OF OUR AREA
IN THE MARGINAL SEVERE WEATHER THREAT AREA...AND THAT SEEMS
REASONABLE GIVEN THE BETTER CHANCE FOR SEEING SOME DAYTIME HEATING
AND PARTIAL SUNSHINE IN THE SOUTHERN PORTION OF THE CWA.
PRECIPITABLE WATER VALUES THIS MORNING ARE GENERALLY IN THE 1.2
INCH RANGE. A FORMIDABLE LLJ OF UP TO 50 KT WAS EVIDENT THROUGHOUT
THE PLAINS AND UPPER MIDWEST.
TODAY...WILL GO WITH FAIRLY HIGH POPS. PRECIPITATION WILL COME IN
WAVES AND INCREASE THROUGHOUT THE DAY. HIGHS SHOULD GENERALLY BE
IN THE 70S...ALTHOUGH SOME 60S ARE POSSIBLE IN SPOTS...WITH 40S
AND 50S NEAR THE LAKE. COULD BE SOME STRONG THUNDERSTORMS DURING
THE LATTER PORTION OF THE DAY...AND POSSIBLY AN ISOLATED SEVERE
THUNDERSTORM ACROSS THE SOUTHEAST HALF OF THE CWA.
TONIGHT...SHOWERS AND THUNDERSTORMS WILL BE LIKELY. A FEW STRONG
STORMS WILL AGAIN BE POSSIBLE DURING THE EVENING...ESPECIALLY
ACROSS THE SOUTHEASTERN PORTION OF THE CWA. BY 06Z FRIDAY...THE
COLD FRONT SHOULD REACH THE DULUTH AREA...AND IT SHOULD JUST ABOUT
CLEAR THE SOUTHEAST CWA BY 12Z FRIDAY. WINDS WILL SWITCH TO THE
NORTHWEST BEHIND THE FRONT.
FRIDAY...THE SHOWERS AND STORMS WILL GRADUALLY DIMINISH FROM THE
WEST. ONLY A FEW SHOWERS WILL LINGER FAR EAST INTO THE AFTERNOON.
DRIER AIR WILL PUSH IN FROM THE NORTHWEST...AS DRIER AND COOLER
AIR SPREADS INTO THE AREA FROM CANADIAN HIGH PRESSURE. HIGHS WILL
BE IN THE 50S FOR MOST OF NE MN...WITH SOME 60S IN WI.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU MAY 7 2015
HIGH PRESSURE AT THE SURFACE WILL BE BUILDING IN ACROSS SRN MANITOBA
AND WRN ONTARIO FRIDAY NIGHT AND SATURDAY...AND INTO LAKE SUPERIOR
SAT NIGHT. AS THE HIGH SHIFTS SLIGHTLY TO THE EAST THE NEXT
SIGNIFICANT LOW PRESSURE SYSTEM WILL MOVE FROM THE SRN PLAINS INTO
THE UPPER MIDWEST BY LATE SUNDAY NIGHT/MON MORNING. THE COMBINATION
OF THE SFC HIGH AND APPROACHING LOW TO THE SOUTH WILL INDUCE A
PERSISTENT E/NE WIND OFF LAKE SUPERIOR FRI NIGHT THROUGH MONDAY
NIGHT. THE APPROACHING SYSTEM WILL ONCE AGAIN DRAW UP A LARGE SUPPLY
OF MOISTURE FROM THE SOUTH AND DEPOSIT IT IN THE FORM OF WIDESPREAD
RAIN SHOWERS ACROSS THE NORTHLAND THROUGH THE DAY SUNDAY AND
CONTINUING INTO MONDAY AS THE SYSTEM WRAPS UP MOVING INTO THE GREAT
LAKES. THIS SYSTEM WILL BE FAIRLY DYNAMIC WITH A STRONG WARM FRONT
OUT AHEAD OF THE LOW...WHICH COULD BE CAPABLE OF PRODUCING SCATTERED
THUNDERSTORMS WITH THE SHOWERS DURING THE DAY SUNDAY. THE SYSTEM
THEN BEGINS TO LOOK MORE LIKE A WINTER-TYPE LOW AS AN AREA OF COLDER
AIR FILLS IN ON THE BACK SIDE...AND A TROWAL-LOOKING FEATURE
DEVELOPS TO THE EAST WITH AN AREA OF ROBUST STRATIFORM RAIN FORMING
IN THE DEFORMATION ZONE ACROSS NRN MN. THE RAIN SHOULD LINGER INTO
LATE MONDAY AND EARLY TUESDAY AS THE COLD AIR CONTINUES TO DROP IN
ACROSS THE UPPER MIDWEST BEHIND THE DEPARTING SYSTEM. THE AMT AND
DEPTH OF THE COLD AIR COULD ACTUALLY CHANGE OVER TO RAIN OR MIX WITH
SNOW AT TIMES TUESDAY MORNING. NO ACCUMULATION IS EXPECTED AT THIS
TIME. HIGH PRESSURE WILL BUILD IN BEHIND THE SYSTEM INTO THE MIDDLE
OF THE WEEK...BUT ONLY FOR A BRIEF PERIOD AS THE NEXT WEAK INVERTED
TROUGH SLIDES IN FROM THE WEST WITH ADDITIONAL CHANCES FOR LIGHT
RAIN.
TEMPERATURES WILL BE NOTICEABLY COOLER THROUGH MUCH OF THE EXTENDED
PERIOD...ESPECIALLY AROUND THE TWIN PORTS AREA WITH A PERSISTENT
E/NE WIND OFF LAKE SUPERIOR. WHILE AREAS INLAND COULD SEE UPPER 50S
AND 60S AT TIMES...LOCATIONS CLOSER TO THE LAKE WILL ONLY SEE 40S
AND LOWER 50S DURING THE DAY. THE PRESENCE OF A LAKE BREEZE WILL
MAKE IT SEEM EVEN COLDER. OVERNIGHT LOWS WILL GENERALLY BOTTOM OUT
IN THE 30S AND LOWER 40S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 637 AM CDT THU MAY 7 2015
RAIN SHOWERS WILL CONTINUE TO MOVE NWD THROUGH THE REGION ALONG
AND AHEAD OF A SLOW MOVING N-S ORIENTED COLD FRONT. WILL LIKELY
SEE THE INITIAL BAND OF SHOWERS MOVE THROUGH THIS MORNING WITH
POSSIBLY A BRIEF BREAK IN THE LATE MORNING AND EARLY AFTERNOON.
SLIGHT DESTABILIZATION IN THE AFTERNOON WILL LEAD TO POSSIBLY A
ROUND OF MORE INTENSE RAIN SHOWERS AND SCATTERED THUNDERSTORMS.
THE SHOWERS AND STORMS COULD LINGER INTO THE EVENING BEFORE
TAPERING OFF AND/OR BECOMING MORE LIGHT AND STRATIFORM INTO THE
LATE EVENING AND OVERNIGHT. THE FRONT WILL PUSH THROUGH LATE
TONIGHT AND FRIDAY MORNING WITH LOW CLOUDS AND RAIN LINGERING.
SHOULD SEE IMPROVEMENT IN CONDITIONS FROM NW TO SE FRI MORNING.
EXPECT GUSTY SOUTH WINDS AHEAD OF THE FRONT TODAY...WITH A SHIFT
TO LIGHT AND VARIABLE NEAR THE FRONT AND VEERING WINDS TO THE NW
BEHIND THE FRONT TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 70 47 58 40 / 80 80 20 0
INL 70 42 53 34 / 80 60 20 0
BRD 72 47 57 39 / 80 70 10 0
HYR 76 53 63 41 / 80 80 20 0
ASX 79 52 62 37 / 70 70 30 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...DAP
LONG TERM...BJT
AVIATION...BJT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
549 AM CDT THU MAY 7 2015
.UPDATED FOR 12Z AVIATION DISCUSSION BELOW...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM CDT THU MAY 7 2015
THE SHORT TERM CONCERNS ARE TIMING AND EXTENT OF CONVECTION AND
TEMPERATURES.
WATER VAPOR IMAGERY IS SHOWING SHORT WAVE TROUGH EXTENSION ACROSS
SOUTHEAST SOUTH DAKOTA INTO IOWA THIS MORNING. AREA OF SHOWERS AND
THUNDERSTORMS ASSOCIATED WITH THIS FEATURE...MOSTLY CONCENTRATED
ACROSS NORTHWEST IOWA/SOUTHWEST MINNESOTA. SPC MESOSCALE ANALYSIS
SHOWING DECENT 850MB MOISTURE TRANSPORT AHEAD OF THE TROUGH...WITH
MORE SHOWERS AND ISOLATED THUNDER DEVELOPING OUT ACROSS CENTRAL MN.
THIS SHOULD CONTINUE TO BE THE TREND AS THIS TROUGH LIFTS
NORTHEAST...AND THE MOISTURE TRANSPORT MAXIMIZES OVER MN. EXPECT AT
LEAST LIKELY POPS AS THIS LIFTS NORTHWEST. THE LATEST HRRR FORECAST
REFLECTIVITY SHOWS THIS TREND AS WELL.
CLOUDS ARE EXPECTED TO REMAIN...THOUGH SOME EROSION MAY OCCUR LATE
THIS MORNING BEFORE CONVECTION REFIRES...OR ENHANCES ONCE AGAIN.
DAY1 OUTLOOK HAS EXPANDED THE MARGINAL SEVERE WEATHER RISK OUT AHEAD
OF THE COLD FRONT. THIS WILL BE FOR THE AFTERNOON/EARLY EVENING
EAST OF THE COLD FRONT. STEEP LAPSE RATES INDICTED AND DEPENDING
HOW MUCH HEATING TAKES PLACE...MODEL FORECAST SURFACE BASED CAPE
INCREASING TO 1500 J/KG. BULK SHEAR IS FORECAST TO RANGE 35-40KTS
ALONG AND EAST OF THE FRONT...WHICH WOULD BE ENOUGH FOR THE
POSSIBILITY OF HAIL AND STRONG WINDS WITH THE STRONGER CONVECTION.
THE MODELED UPDRAFT HELICITY WAS INDICATING THE MAIN THREAT OVER
WEST CENTRAL WISCONSIN...WITH WHAT APPEARS TO BE A LEADING SURFACE
TROUGH. WILL HAVE TO MONITOR CLOUD TRENDS AND SEE IF INDEED
INSTABILITY WILL INCREASE ENOUGH TO GENERATE A SMALL SEVERE WEATHER
RISK OVER THE EASTERN CWA.
THE FRONT MOVES INTO WESTERN WISCONSIN THIS EVENING AND SHOULD TAKE
THE BULK OF THE SHOWERS WITH IT. THERE IS SOME THREAT OF MID LEVEL
SHRA DEVELOPING BEHIND THE COLD FRONT INTO CENTRAL MN LATER TONIGHT.
THE MODELS WERE INDICATING SOME STRONGER MID LEVEL FGEN. BUT IT
REMAINS TO BE SEEN IF THERE WILL BE ENOUGH MOISTURE TO CONTINUE THE
SHOWER THREAT. STILL MAINTAINED THE SMALL CHANCE POPS AFTER 06Z
FRI FOR NOW.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 350 AM CDT THU MAY 7 2015
BY FRIDAY MORNING...THE AFOREMENTIONED COLD FRONT AND SURFACE LOW
RESPONSIBLE FOR THE RAIN IN THE SHORT TERM WILL BE EAST OF THE
FORECAST AREA. HIGH PRESSURE WILL BUILD IN ACROSS THE NORTHERN
HIGH PLAINS ON FRIDAY AND INTO THE UPPER MISSISSIPPI RIVER VALLEY
ON SATURDAY. THE POST FRONTAL AIR MASS ON FRIDAY WILL BE QUITE
COOL WITH TEMPERATURES IN CENTRAL/NORTHERN MN LIKELY REMAINING IN
THE 50S DURING THE AFTERNOON. WE MIGHT EVEN BE A LITTLE TOO WARM
WITH FRIDAY`S TEMPERATURES...ESPECAILLY GIVEN THE DECENT CHANCE
FOR A BROKEN TO OVERCAST DECK OF MID CLOUDS. THE WEATHER SHOULD
REMAIN DRY ON FRIDAY. ON SATURDAY...A WEST COAST TROUGH WILL EJECT
EAST OUT OF CALIFORNIA AND PASS OVER THE ROCKIES BEFORE SLOWLY
MAKING ITS TRACK ACROSS THE REGION SUN-TUE. A SURFACE LOW IS
FORECAST TO TRACK FROM THE CENTRAL PLAINS...ACROSS IA...AND
EVENTUALLY REACHING EASTERN LAKE SUPERIOR BY TUESDAY. THAT PUTS
MN/WI IN A PRETTY GOOD SPOT FOR WIDESPREAD RAIN SUNDAY INTO
MONDAY. THE 06.18Z AND 07.00Z RUNS OF THE GFS DEPICT SIMILIAR
SOLUTIONS...A CHANGE FROM THE FEW RUNS BEFORE THESE LAST TWO WHICH
HAD A LOT OF RUN-TO-RUN VARIABILITY IN HOW IT HANDLED THE
PROGRESSION OF THIS SURFACE LOW EARLY NEXT WEEK. THE GFS IS
HEAVIER WITH THE QPF WHEN COMPARED TO THE ECMWF...BECAUSE IT IS
ALSO SLOWER...DEEPER...AND FARTHER SOUTH THAN THE ECMWF. THE ECMWF
HAS ALSO HAD A COUPLE RUNS NOW WITH BETTER CONSISTENCY. WE TRENDED
THE TEMPS A BIT COOLER MON-WED...WITH THE FREEZING LEVEL JUST A
COUPLE THOUSAND FEET OFF THE GROUND TUE-WED. TEMPERATURES REALLY
DO NOT START TO MODIFY UNTIL AT LEAST THURSDAY. SO...MN/WI IS IN
FOR A COOL WEEK AFTER THE RAIN MOVES TUE-TUE NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 545 AM CDT THU MAY 7 2015
BAND OF SHOWERS/ISOLATED THUNDER LIFTING NORTH AHEAD OF THE
DAKOTAS TROUGH. EXPECT THIS TO GRADUALLY WEAKEN AND LIFT OFF TO
THE NORTH. OTHERWISE...REDEVELOPMENT LIKELY BY 18Z...MAINLY SHRA
WITH EMBEDDED THUNDER...ESPECIALLY ALONG EASTERN TROUGH AXIS AND
REAL COLD FRONT PUSHING IN FROM THE NORTHWEST. ACTIVITY SHOULD
WANE TO THE WEST THROUGH 06Z AND JUST AFTER 06Z TO THE FAR EAST.
EXPECT MVFR CONDITIONS WITH THE THUNDER AND THEN WITH BAND OF
CLOUDS DEVELOPING BEHIND THE COLD FRONT. THAT SHOULD PUSH INTO
KAXN BY 00Z AND THEN MOVE OUT BY 07Z. SOUTHEAST TO SOUTH WINDS ARE
GUSTY INTO THE DAY...AND WILL BECOME NORTHWEST WITH FROPA.
KMSP...
BAND OF -SHRA MOVING THROUGH THROUGH ABOUT 14Z...AND REDEVELOPMENTTHIS
AFTERNOON. MENTIONED TSRA IN THE 20-24Z PERIOD FOR NOW. FROPA MOVES
IN AROUND 06Z WITH A BAND OF MVFR CIGS EXPECTED THROUGH AT LEAST
15Z FRI. SOME QUESTION AS TO HOW LOW TO GO IN CIGS. RIGHT NOW AM
CONFIDENT ENOUGH TO MENTION 1500 FT AFTER 10Z.
/OUTLOOK FOR KMSP/
FRI AFTERNOON/NIGHT...VFR. WINDS NW 10 KTS.
SAT...VFR. WINDS NE 10 KTS.
SUN...MVFR LIKELY WITH IFR POSSIBLE IN SHWRS/TSTMS. WINDS NE
10-15 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...DWE
LONG TERM...CLF
AVIATION...DWE
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
704 AM CDT Thu May 7 2015
.SHORT TERM: (Today and Tonight)
Issued at 339 AM CDT Thu May 7 2015
Short-range guidance has been consistently spitting out some sunrise
surprise showers for the past few runs. The RAP might be a little
overdone as it looks like it`s trying to break pieces of the MCV
currently over Oklahoma off and spread them northeast across the
area. That being said, radar is picking up some very light echos
developing over the eastern Ozarks at this time...so the possibility
for isolated showers does seem to be increasing this morning.
Aside from any morning showers, expect most of the morning and early
afternoon to be dry. Should see highs today similar to if not a bit
warmer than Wednesday. The MCV should lift up into the area and
provide a lifting mechanism later this afternoon. Additionally,
the cold front now over western Nebraska/Kansas will drift into
western/northwestern Missouri by late this afternoon providing an
additional focusing mechanism. Think likely PoPs across central and
northeast Missouri into west central Illinois look good with chance
PoPs further to the southeast still look good for the afternoon into
early evening. PoPs for the rest of the night are less certain
though, and short-range guidance seems to be having as much trouble
as I am figuring out how to handle the situation. MOS guidance
ranges from low chance to categorical across the area. GFS and NAM
do show a weak to moderate low level jet setting up during the
evening, with a few waves of moisture convergence in the warm sector
ahead of the front. Baroclinicity is weak, but present, so I cannot
rule out scattered to possibly numerous showers and
thunderstorms...particularly closer to the front in central and
northeast Missouri.
Carney
.LONG TERM: (Friday through Wednesday)
Issued at 410 AM CDT Thu May 7 2015
Southwest flow aloft will continue to try to bring deeper moisture
back to the Mississippi Valley Friday into the weekend. It`s
difficult to really pick out a time when thunderstorms are more or
less likely for Friday through Sunday as the foci for precipitation
will likely be fast-moving shortwaves moving over the area in the
southwest flow aloft, as well as low level boundaries from
convection. Models have the synoptic front generally draped across
northern Missouri...possibly dipping down as far south as the
Missouri river at times as it is forced south by convection. Have
some flavor of 40-70% PoPs across the area for Friday through
Saturday night with the higher end PoPs closer to the synoptic
front. Guidance has the high amplitude closed wave finally opening
up and moving int the Great Plains on Sunday with the resulting
surface low moving northeast from Kansas through Iowa into the Great
Lakes Sunday night through Monday. Resulting cold front should
sweep through the forecast area late Sunday night into early Monday
morning. Cooler and drier air will bring an end to the rain chances
by most likely by Monday afternoon. Above normal temperatures will
continue ahead of the FROPA on Monday with highs mainly in the 80s
and lows in the mid 60s. Medium range guidance drops temperatures
back below normal for Tuesday and Wednesday showing highs mainly 65
to 70 and lows mainly in the upper 40s and low 50s.
Carney
&&
.AVIATION: (For the 12z TAFs through 12z Friday Morning)
Issued at 640 AM CDT Thu May 7 2015
Fairly complex aviation forecast with southwest flow aloft in
place and a number of weak disturbances progged to translate
within the flow across the area. Adding to the difficulty are
model solutions that vary widely with the timing and placement of
the thunderstorms. Present thinking is that thunderstorms will
develop by early afternoon in central MO and then move east-
northeastward impacting both KCOU and KUIN which is reflected in
the TEMPO groups. Confidence is a bit less for the St. Louis
terminals as they may be on the southern end of the thunderstorms
and hence just went with a PROB30. One of the disturbances will
move across the region tonight and this should produce another
round of showers and thunderstorms from late evening into the
overnight hours. Since confidence is low on the specifics of timing
and coverage I only forecast showers and VCTS for this later
round. Outside of the showers and thunderstorms, VFR flight
conditions should prevail.
Specifics for KSTL:
Present thinking is that thunderstorms will develop by early
afternoon in central MO and then move east-northeastward. The main
question is if they will impact KSTL. Confidence is low as KSTL
may be on the southern end of the thunderstorms and hence just
went with a PROB30. A disturbance aloft will move across the
region tonight and this should produce another round of showers
and thunderstorms that could impact KSTL late tonight into Friday
morning. Since confidence is low on the specifics of timing and
thunder coverage I only forecast showers and VCTS for this later
round. Outside of the showers and thunderstorms, VFR flight
conditions should prevail.
Glass
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
815 AM MDT THU MAY 7 2015
.UPDATE...
SNOW IS FALLING AT LIVINGSTON...NYE AND BOZEMAN PASS THIS MORNING
THANKS TO WET BULB COOLING TO 32 F WITHIN THE BOUNDARY LAYER. THE
FORECAST WAS UPDATED TO REFLECT THIS WITH A MIX OF RAIN AND SNOW
NOW MENTIONED ALONG THE FOOTHILLS THROUGH THE MORNING. ROADS ARE
JUST WET AND SHOULD REMAIN THAT WAY. THE HRRR APPEARS TO HAVE A
GOOD HANDLE ON THIS SCENARIO AND CONFIRMS THAT A DOWNWARD TREND
SHOULD COMMENCE IN PRECIPITATION THIS AFTERNOON. POP-WISE...THE
FORECAST WAS ADJUSTED TO REFLECT CATEGORICAL POPS OF 100 PERCENT
IN AND AROUND LIVINGSTON THIS MORNING...BUT CONVERSELY WE CHOSE
TO DROP THE SLIGHT CHANCE OF RAIN SHOWERS COMPLETELY OUT OF THE
FORECAST FOR BILLINGS BASED ON RECENT RADAR AND HRRR MODEL TRENDS.
FINALLY...WE LOWERED FORECAST HIGHS SEVERAL DEGREES IN AND NEAR
THE FOOTHILLS LIKE AT LIVINGSTON GIVEN CLOUDS...MOISTURE AND AN
EASTERLY LOW-LEVEL FLOW IN THOSE AREAS TODAY. SCHULTZ
&&
.SHORT TERM...VALID FOR TDY AND FRI...
EARLY THIS MORNING...RADAR RETURNS ARE ALREADY BEGINNING TO
INCREASE OVER THE SOUTHWESTERN MOUNTAINS AND FOOTHILLS. THIS IS
ASSOCIATED WITH A SHORT WAVE MOVING OUT OF UTAH. AS THIS
CONTINUES TO MOVE NORTH...RAIN CHANCES WILL INCREASE THROUGH THE
MORNING. WINDS ACROSS THE AREA ARE GOING TO REMAIN OUT OF NORTH TO
NORTHEAST. WITH THE UPSLOPE COMPONENT ALONG WITH THE AREA STILL
SOMEWHAT IN A FAVORABLE REGION OF A 250MB JET...AND THROW IN SOME
QG FORCING...RAIN LOOKS LIKELY OVER THE MOUNTAINS AND WESTERN
ZONES DURING THE DAY TODAY. HI-RES GUIDANCE SHOW PRECIP PUSHING
ALMOST TO BILLINGS...SO HAVE LEFT A SLIGHT CHANCE IN FOR THE CITY.
MOST OF THE RAIN ASSOCIATED THE A SHORTWAVE IN THE DAKOTAS HAS
ALREADY MOVED OUT OF MONTANA. HAVE REMOVED POPS FROM MOST OF CARTER
AND FALLON COUNTIES...LEAVING MUCH OF THE AREA EAST OF BILLINGS
AND SHERIDAN DRY THROUGH THE DAY.
OVERNIGHT RAIN CHANCES WILL DECREASE SOME AS THIS AROUND OF ENERGY
DISSIPATES...BUT THE BEST CHANCES IN THE SHORT TERM WILL BE
FRIDAY EVENING. AS THE CLOSED LOW MOVES INTO THE FOUR CORNERS
REGION...THE AREA WILL SEE ANOTHER ROUND OF ENERGY MOVE IN. WINDS
WILL SHIFT TO MORE EASTERLY DURING THE DAY FRIDAY AND MOISTURE
WILL BE INCREASING. THIS WILL COMBINED WITH INCREASINGLY DIFFLUENT
FLOW ALOFT TO GIVE MUCH OF THE AREA A SHOT AT RAIN. TEMPERATURES
AT 850MB CONTINUE TO BE IN THE 0 TO +3 DEGREE RANGE ACROSS THE
AREA. IN THE MOUNTAINS THIS WILL RESULT IN SNOWFALL OF 2 TO 4
INCHES OF SNOW...SOME LOCALLY HIGHER AMOUNTS CLOSER TO 6...FRIDAY
INTO EARLY SATURDAY. THE FOOTHILLS WILL SEE LESS...GENERALLY A
COUPLE OF INCHES OF SNOW OVER 24 HOURS. MAINTAINED THE PREVIOUS
FORECAST OF ONLY RAIN IN BILLINGS AND POINTS FURTHER EAST AS
GUIDANCE CONTINUES TO SHOW WETBULB TEMPERATURES REMAIN SLIGHTLY
ABOVE FREEZING. REIMER
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
MEDIUM RANGE GUIDANCE IN FAIRLY GOOD AGREEMENT INTO THE EXTENDED.
SATURDAY STILL LOOKING LIKE A COOL AND WET DAY UNDER UPPER
DIFFLUENT FLOW AHEAD OF UPPER LOW DRIFTING EAST ACROSS THE
SOUTHERN ROCKIES. AS SYSTEM SPINS UP INTO THE PLAINS...A DRIER
NORTHWEST FLOW PUSHES INTO MOST OF OUR AREA FOR SUNDAY. THE MAIN
CHANGES INTO THE EXTENDED WAS TO LOWER PRECIPITATION CHANCES FOR
SUNDAY WITH THE SYSTEM TRENDING FURTHER SOUTHEAST. AS UPPER LOW
DRIFTS EAST INTO THE MIDWEST...A NORTH/NORTHWEST FLOW DOMINATES
INTO TUESDAY FOR OVERALL DRY CONDITIONS. ONCE WEDNESDAY
APPROACHES...INTRODUCED CLIMO PRECIP CHANCES AS FLOW BECOMES MORE
SOUTHWEST AGAIN AND INSTABILITY INCREASES ACROSS THE REGION. NO
ORGANIZED SYSTEM...JUST MAINLY SCATTERED AFTERNOON SHOWERS.
AS FOR TEMPERATURES...READINGS COULD BE AS MUCH AS 20 DEGREES
BELOW NORMAL FOR SATURDAY IF THE CLOUDY AND WET CONDITIONS EVOLVE
AS EXPECTED. A SLOW MODERATION IN TEMPERATURES EXPECTED THE REST
OF THE EXTENDED. THE NORTHWEST FLOW BEHIND THE WEEKEND SYSTEM WILL
KEEP TEMPERATURES BELOW NORMAL INTO MONDAY. FRIEDERS
&&
.AVIATION...
AREAS OF RAIN AND SNOW SHOWERS WILL OCCUR IN THE MOUNTAINS AND
FOOTHILLS WITH FREQUENT TO OCCASIONAL LIFR...ESPECIALLY THIS
MORNING. CONDITIONS WILL SLOWLY IMPROVE THIS AFTERNOON IN THESE
AREAS. ALSO...EXPECT LOCAL MVFR AROUND KBHK AT TIMES THIS
MORNING. OTHERWISE...VFR CONDITIONS WILL PREVAIL WITH A MID LEVEL
CLOUD DECK. BT
&&
.PRELIMINARY POINT TEMP/POPS...
TDY FRI SAT SUN MON TUE WED
-------------------------------------------------------
BIL 052 038/047 036/043 035/053 035/058 038/065 044/069
1/E 14/W 77/R 61/B 11/B 11/B 12/W
LVM 044 033/046 033/044 032/051 030/057 035/063 038/066
+/W 26/W 77/O 52/W 12/W 22/W 33/W
HDN 055 036/054 036/045 033/055 033/060 034/066 041/070
1/E 13/W 77/R 61/B 11/B 11/B 12/W
MLS 056 036/056 037/050 033/055 034/060 038/064 042/069
1/E 12/W 55/R 31/B 10/B 11/B 12/W
4BQ 055 034/058 038/045 031/050 032/056 034/062 041/068
1/E 12/W 66/R 62/W 10/B 11/B 12/W
BHK 054 032/056 034/050 031/051 031/056 034/059 038/065
1/N 11/E 34/R 21/B 10/B 11/B 12/W
SHR 052 033/053 035/041 030/047 030/054 033/062 039/066
4/W 14/W 78/O 63/W 21/B 11/B 12/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
621 AM CDT THU MAY 7 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 318 AM CDT THU MAY 7 2015
SHOWERS AND THUNDERSTORMS CONTINUE MAINLY ACROSS THE SOUTHEAST PART
OF THE FORECAST AREA. SURFACE ANALYSIS SHOWS A LOW PRESSURE SYSTEM
AND COLD FRONT JUST TO THE WEST OF THE FORECAST AREA AT THIS TIME.
MODELS ARE FAIRLY CONSISTENT KEEPING THE CURRENT PRECIPITATION
ACROSS MAINLY THE EASTERN PART OF THE FORECAST AREA THROUGH DAYBREAK
OR INTO THE MORNING HOURS...BUT WHEN IT MOVES OUT THERE SHOULD BE A
BREAK IN THE PRECIPITATION FOR A TIME. THE COLD FRONT TO THE WEST OF
THE FORECAST AREA THIS MORNING IS EXPECTED TO MOVE THROUGH THE AREA
DURING THE DAY. MODELS HAVE SOME DIFFERENCES ON HOW FAST IT MOVES
THROUGH. THE GFS HAS IT MOST OF THE WAY THROUGH THE FORECAST AREA BY
MID DAY WHILE THE NAM IS SLOWER TO MOVE THROUGH. THE RAP IS CLOSER
TO THE GFS AND MOVES IT THROUGH FASTER. WENT A LITTLE IN BETWEEN AND
HAVE IT IN THE EAST AND SOUTHERN PARTS OF THE FORECAST AREA MID
AFTERNOON. THE LOCATION OF THE FRONT IS IMPORTANT AS THE NEXT UPPER
LEVEL WAVE MOVES INTO THE FORECAST AREA DURING THE LATE AFTERNOON
AND INTO TONIGHT. THE UPPER WAVE MOVES IN FROM THE SOUTHWEST SO THE
PRECIPITATION SHOULD MOVE IN FROM THE SOUTH DURING THE AFTERNOON AND
SPREAD ACROSS MUCH OF THE AREA. THE BEST CHANCES WILL BE IN THE
SOUTH OR SOUTHEAST TONIGHT. WILL HAVE TO WATCH THE SOUTHEAST...THIS
IS THE AREA WITH ONGOING FLOODING AND THE AREA THE MOST LIKELY TO
HAVE PRECIPITATION TONIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 318 AM CDT THU MAY 7 2015
GUIDANCE SUGGESTS AN UPPER TROPOSPHERIC LOW WILL EXIST OVER THE
SOUTHWESTERN CONUS TO START THE LONG-TERM FORECAST PERIOD AT 12Z
FRIDAY...WITH UPPER TROPOSPHERIC RIDGING OVER THE EASTERN CONUS.
THIS UPPER TROPOSPHERIC LOW IS EXPECTED TO MOVE NORTHEAST FRIDAY
THROUGH EARLY NEXT WEEK...LIKELY CLEARING THE CENTRAL PLAINS
SATURDAY INTO SUNDAY. QUASI-ZONAL UPPER TROPOSPHERIC FLOW IS THEN
EXPECTED ACROSS THE REGION DURING THE EARLY TO MIDDLE PART OF NEXT
WEEK.
GUIDANCE SUGGESTS UPPER TROPOSPHERIC THERMAL ADVECTION AHEAD OF THE
APPROACHING LOW WILL PROMOTE PRECIPITATION PRODUCTION ACROSS OUR AREA
FRIDAY THROUGH EARLY NEXT WEEK...WITH PERHAPS A RELATIVELY DRY
PERIOD AT SOME POINT EARLY NEXT WEEK AS THE AFOREMENTIONED UPPER
TROPOSPHERIC LOW CLEARS THE REGION. THAT SAID...GUIDANCE ALSO
SUGGESTS MULTIPLE UPPER TROPOSPHERIC PERTURBATIONS...EMBEDDED WITHIN
THE DEVELOPING QUASI-ZONAL FLOW...COULD PROMOTE ADDITIONAL
PRECIPITATION CHANCES DURING THE MIDDLE TO LATE PART OF NEXT WEEK.
GIVEN ALL THIS...POPS REMAIN INTACT ACROSS THE AREA DURING MUCH OF
THE LONG-TERM FORECAST PERIOD...WITH THE HIGHEST POPS EXISTING
BETWEEN SATURDAY AFTERNOON AND SATURDAY NIGHT AS THE UPPER
TROPOSPHERIC LOW CLEARS THE AREA.
A DRIER BOUNDARY-LAYER AIR MASS...ALONG WITH MODEST UPPER
TROPOSPHERIC LAPSE RATES...SHOULD KEEP SEVERE WEATHER AT BAY FRIDAY
INTO FRIDAY NIGHT...WITH GUIDANCE SUGGESTING POTENTIAL ENERGY WILL
REMAIN AT OR BELOW 500J/KG ACROSS MUCH OF THE CWA. THAT WILL CHANGE
FOR PORTIONS OF THE REGION SATURDAY INTO SATURDAY NIGHT HOWEVER AS
BOUNDARY-LAYER MOISTURE FLUX ACROSS THE CENTRAL PLAINS...ALONG WITH
INCREASING UPPER TROPOSPHERIC LAPSE RATES WITH THE APPROACH OF THE
UPPER TROPOSPHERIC LOW...PROMOTES POTENTIAL ENERGY ON THE ORDER OF
~1500J/KG ACROSS SOUTHERN PORTIONS OF THE CWA...AND LOWER POTENTIAL
ENERGY AS ONE MOVES NORTH ACROSS THE AREA. THESE POTENTIAL ENERGY
VALUES...WORKING IN CONCERT WITH DEEP-LAYER BULK SHEAR VALUES OF
AROUND 50KTS...COULD PRESENT YET ANOTHER OPPORTUNITY FOR SEVERE
WEATHER ACROSS PORTIONS OF THE CWA SATURDAY AFTERNOON INTO SATURDAY
NIGHT...ESPECIALLY ACROSS OUR SOUTHERN COUNTIES SOUTH OF HIGHWAY 6.
GIVEN THIS...WILL CONTINUE MENTIONING SEVERE WEATHER IN THE HWO
SATURDAY INTO SATURDAY NIGHT GENERALLY SOUTH OF HIGHWAY 6. DRIER
BOUNDARY-LAYER AIR AND DECREASING UPPER TROPOSPHERIC LAPSE RATES
SHOULD THEN ALLOW FOR A DECREASING SEVERE WEATHER THREAT AS WE MOVE
INTO THE EARLY PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 618 AM CDT THU MAY 7 2015
CLOUDS ARE EXPECTED TO BREAK UP LATER THIS MORNING OR EARLY THIS
AFTERNOON THEN REDEVELOP LATER TONIGHT. A COLD FRONT IS EXPECTED
TO MOVER THROUGH THE AREA TURNING WINDS TO THE NORTHWEST.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...JCB
LONG TERM...BRYANT
AVIATION...JCB
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
623 AM EDT THU MAY 7 2015
.SYNOPSIS...
LOW PRESSURE SOUTH OF CAPE FEAR MAY BECOME A SUBTROPICAL CYCLONE
OVER THE NEXT COUPLE OF DAYS. THE SYSTEM IS EXPECTED TO APPROACH
THE COAST OF SOUTH CAROLINA OR SOUTHERN NORTH CAROLINA FRIDAY AND
SATURDAY WITH INCREASING CHANCES FOR HEAVY RAIN...GUSTY WINDS...
AND DANGEROUS RIP CURRENTS AT THE BEACHES. THIS SYSTEM WILL ONLY
GRADUALLY LIFT NORTH AWAY FROM THE AREA EARLY NEXT WEEK. A COLD
FRONT WILL APPROACH NEXT WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM THURSDAY...BASED ON PROGRESS OF RAIN SHIELD WESTWARD
HAVE INCREASED POPS FURTHER THIS MORNING TO 100 PERCENT FOR THE
COASTAL AREAS FROM THE MYRTLES NORTHWARD. HAVE ALSO RAISED POPS
FOR OTHER AREAS FURTHER WESTWARDS. PREVIOUS DISCUSSION FOLLOWS:
EXTENSIVE RAIN SHIELD APPROACHING AND NOW SKIRTING THE COAST IS
HAVING TROUBLE HOLDING TOGETHER OVER LAND AS IT HAS TO OVERCOME A
VERY DRY MID LAYER. THE TEMP-DEWPOINT SPREAD AT THE 850 MB LEVEL
IS AROUND 45 DEGREES JUST INLAND OF THE COASTAL COUNTIES THIS
MORNING ACCORDING TO MODEL SOUNDINGS...SO ALTHOUGH THE BEACHES ARE
FINALLY SEEING SOME PATCHY LIGHT RAIN WITH CIGS AROUND 10
KFT...PROGRESS FURTHER WESTWARD WILL CONTINUE TO BE SLOW AND
UNEVEN. RADAR SHOWS A NARROW BAND OF HEAVIER RAIN ABOUT 20 NM
OFFSHORE. UNLESS THAT BAND GETS HERE INTACT WE CAN EXPECT ANY
ACCUMULATIONS TO BE ONLY ON THE VERY LIGHT SIDE THIS MORNING.
NHC NOW HAS THE NON-TROPICAL LOW PRESSURE SYSTEM AROUND 220 MILES
SSE OF THE SC/NC BORDER AND GIVES A 70 PERCENT CHANCE OF CYCLONE
FORMATION WITHIN 48 HOURS. SATELLITE LOOPS SHOW BETTER ORGANIZATION
AND A MORE DISTINCT CIRCULATION CENTER...WHICH IS BEING ANALYZED AT
AROUND 1009 MB. GUIDANCE IN REL GOOD AGREEMENT FOR THE NEAR TERM AS
FAR AS MOVEMENT GOES...WITH THE SYSTEM DRIFTING NW TOWARDS COASTAL
NC/SC. ALL MODELS SHOW DEEPENING WITH THE NAM BEING THE MOST
AGGRESSIVE. HAVE LEANED ON A BLEND OF GUIDANCE TO ACCOUNT FOR BOTH
THE UNCERTAINTY OF THE SITUATION AND AGREEMENT BETWEEN GUIDANCE.
EXPECT WINDS TO PICK UP FROM THE NE TODAY AS THE SYSTEM MOVES
NW...BUT THE RELATIVELY MODERATE ASSOCIATED GRADIENT WILL KEEP WINDS
IN THE 15 KT RANGE THIS AFTERNOON WITH GUSTS OF 20 KTS OR SO. PRECIP
WILL BE THE TRICKY ELEMENT OF THE FORECAST. GIVEN RECENT TRENDS AND
PROJECTED MOVEMENT OF THE SYSTEM HAVE UPPED POPS TO CATEGORICAL FOR
TODAY FOR THE COASTAL COUNTIES...TRENDING DOWNWARD AS ONE MOVES
INLAND. RETAINING POSSIBILITY OF THUNDER OVERNIGHT AS SYSTEM
APPROACHES THE COAST.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 330 AM THURSDAY...THE CHALLENGE...UNSURPRISINGLY...THROUGH
THE SHORT TERM REMAINS DETERMINING WHAT KIND OF IMPACT A
STRENGTHENING LOW PRESSURE WILL HAVE ON THE AREA. RECON FROM NHC
WAS CANCELLED YESTERDAY AFTN DUE TO LACK OF ORGANIZATION...AND
CURRENT WV/IR IMAGERY IS LESS THAN IMPRESSIVE...ALTHOUGH
IMPROVING. HOWEVER...GUIDANCE IS STARTING TO COME TO SOME GENERAL
CONSENSUS ON A SLOWER AND OVERALL WEAKER SYSTEM MEANDERING JUST
OFF THE COAST THROUGH THE PERIOD. LOW PRESSURE WILL LIFT NORTH TO
SOME WHERE JUST OFF THE SC COAST BEFORE THE PERIOD...AND THEN
STALL...LOOP...OR RETROGRADE BACK TOWARDS THE SW AS ITS MOTION
GETS HALTED BY RIDGE TO THE NORTH. VERY SLOW MOVEMENT IS EXPECTED
REGARDLESS OF THE ACTUAL TRACK...AND IT IS NEARLY GUARANTEED THAT
THIS WILL BE IMPACTING THE AREA ALL FRIDAY AND SATURDAY. A SLOWLY
LOOPING SYSTEM JUST OFFSHORE WILL MAINTAIN RAIN CHANCES...SOME OF
WHICH MAY BE HEAVY AT TIMES...THE CHANCE FOR SOME GUSTY WINDS
(FOCUSED ALMOST EXCLUSIVELY ALONG THE COAST HOWEVER)...AS WELL AS
HIGH WAVE ACTION/MINOR BEACH EROSION/STRONG RIP CURRENTS.
THE BIGGEST IMPACT LOCALLY IS LIKELY TO END UP BEING
RAINFALL...ESPECIALLY FROM MYRTLE BEACH NORTHWARD ACROSS THE CAPE
FEAR COAST. GUIDANCE SUGGESTING THAT 250MB DIFFLUENCE WILL BE ALMOST
EXCLUSIVELY ON THE N AND E SIDE OF THE SYSTEM (MORE EVIDENT IT WILL
NEVER TRULY BECOME TROPICAL EVEN AS FSU PHASE DIAGRAMS SUGGEST
SYMMETRIC WARM CORE DEVELOPMENT) WHICH SUGGESTS CONVECTION WILL BE
CONFINED TO THE N/E SIDE OF THE SYSTEM. WITH THE LOW STALLING JUST
SE OF THE AREA...COPIOUS MOISTURE WILL ADVECT FROM AN ANOMALOUSLY
HIGH PWAT AIRMASS...SO SOME VERY HEAVY RAIN WILL AT LEAST LURK
OFFSHORE...AND MAY ADVECT INLAND. A TIGHT AND SIGNIFICANT GRADIENT
WILL EXIST...AND CONVECTIVE ELEMENTS ARE POSSIBLE AS MOIST-ADIABATIC
LAPSE RATES EXIST DEEP INTO THE COLUMN. HIGHEST POP WILL REMAIN
FRIDAY ESP ALONG THE COAST...BUT A GOOD CHC FOR RAINFALL WILL
CONTINUE RIGHT TROUGH SATURDAY NIGHT.
TEMPS WILL STRUGGLE EVEN IN THE TROPICAL AIR MASS DUE TO WIDESPREAD
CLOUDS AND RAIN. HIGHS WILL REMAIN BELOW CLIMO...MID 70S FRIDAY AND
UPR 70S SATURDAY...BUT TEMPERED DIURNAL RANGES WILL KEEP MINS IN THE
UPR 60S OR CLOSE TO 70 BOTH NIGHTS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 330 AM THURSDAY...FIRST HALF OF THE EXTENDED WILL CONTINUE
TO FEATURE A SLOW MOVING LOW PRESSURE SYSTEM SOMEWHERE IN THE
VICINITY. THIS LOW PRESSURE WILL MEANDER JUST OFFSHORE OR POSSIBLY
JUST INLAND OF THE COAST SUNDAY AND MONDAY AS STEERING FLOW
REMAINS GENERALLY WEAK. WHILE A WEAKENING TREND IS EXPECTED DURING
THE LONG TERM...THE HIGHEST PWAT AIR MAY ACTUALLY MOVE ACROSS THE
CWA SUNDAY...SO PERIODS OF HEAVY RAINFALL COULD CONTINUE AT LEAST
INTO MONDAY. WILL NOT FOCUS ON ANY SPECIFICS AT THIS TIME
RANGE...AND JUST SHOW CONTINUED UNSETTLED WEATHER WITH CHC
POP...HIGHEST ACROSS THE CAPE FEAR REGION...WITH PERIODS OF MDT TO
POSSIBLY HVY RAINFALL. THE LOW WILL FINALLY KICK OUT TO THE NE ON
TUESDAY AS AN UPPER TROUGH DIGS INTO THE GREAT LAKES REGION. THE
UNSETTLED CONDITIONS WILL PERSIST INTO WEDNESDAY HOWEVER AS A COLD
FRONT DIGS ACROSS THE CAROLINAS AT THE END OF THE PERIOD. THERE IS
GOOD NEWS HOWEVER...AS THIS FRONT SHOULD BRING IN A PERIOD OF MUCH
DRIER CONDITIONS BEYOND THIS FORECAST PERIOD.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
AS OF 06Z...CONFIDENCE IS STILL RATHER LOW...BUT IMPROVING AS THE
MODELS ARE STARTING TO GET A BIT MORE IN SYNC. LOW PRESSURE WILL
SLOWLY APPROACH THE REGION TOWARD MORNING...WITH SHOWERS AND MVFR
CONDITIONS EXPECTED AN HOUR OR TWO AFTER DAYBREAK ALONG THE COAST.
AGAIN...THE UNCERTAINTY IS THERE AS THE HRRR MODEL IS SLOWER THAN
THIS. THE GRADIENT WILL TIGHTEN ALSO AROUND DAYBREAK...WITH GUSTS
OVER 20 KTS A GOOD BET AFTER 14Z. THE INLAND TERMINALS WILL TAKE A
WHILE TO GET ANY PRECIP...PERHAPS BY MID AFTERNOON. THE COLUMN OF
DEEP MOISTURE WILL REMAIN OVER THE REGION THROUGH THE END OF THE
FORECAST PERIOD...WITH INTERMITTENT IFR POSSIBLE IN THE HEAVIER
PRECIP.
EXTENDED OUTLOOK...RAIN/MVFR. TEMPO IFR IN HEAVIER SHOWERS HIGHEST
CONFIDENCE COASTAL TERMINALS. BECOMING VFR/SHOWERS SUNDAY. VFR
ISOLATED SHOWERS MON.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM THURSDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSION FOLLOWS:
SMALL CRAFT ADVISORY WILL CONTINUE THROUGH THE NEAR TERM AS A LOW
PRESSURE SYSTEM 220 MILES SSE OF THE NC/SC BORDER DRIFTS NW.
EXPECT WINDS AND SEAS TO BE HIGHEST OVER OUR SC WATERS...WITH 20
TO 25 KTS AND 5 TO 8 FT RESPECTIVELY FOR TODAY. CONDITIONS WILL BE
A BIT BETTER FOR OUR NC WATERS...BUT WILL STILL BE HAZARDOUS WITH
SEAS IN THE 5 TO 7 FT RANGE.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 330 AM THURSDAY...STRENGTHENING LOW PRESSURE WILL MEANDER
VERY NEAR THE COASTAL WATERS THROUGH THE ENTIRE PERIOD...CREATING
PERIODS OF GUSTY WINDS AND LARGE WAVES. WHILE UNCERTAINTY REMAINS
IN THE EXACT INTENSITY AND PLACEMENT OF THIS SYSTEM AS IT
EVOLVES...REGARDLESS OF THE EVENTUAL SOLUTION CONDITIONS WILL BE
DIFFICULT FOR MARINERS. WITH THE CURRENT FORECAST PATH EXPECTED TO
KEEP THE LOW CENTER EAST OF THE SC...WINDS WILL BE GENERALLY
EASTERLY ACROSS AMZ250 AND AMZ252...AND NORTHERLY OVER AMZ254 AND
AMZ256. THESE SHOULD REMAIN FAIRLY CONSISTENT THROUGH THE
PERIOD...ALTHOUGH SOME FLUCTUATION CAN BE EXPECTED...ESPECIALLY AS
THE LOW WOBBLES IN THE VICINITY. SPEEDS REGARDLESS OF DIRECTION
WILL BE 15-25 KTS...WITH SOME GUSTS OVER 30 KTS
POSSIBLE...PRIMARILY OVER THE NC WATERS.
WAVE HEIGHTS WILL BE HIGHEST ACROSS NC WATERS THANKS TO THE ONSHORE
FLOW WHERE 5-9 FT SEAS ARE EXPECTED FRIDAY. 4-7 FTERS ARE
ANTICIPATED ACROSS THE SC WATERS. SEAS WILL GRADUALLY START TO COME
DOWN THE LATTER HALF OF THE PERIOD BUT THIS WILL OBVIOUSLY DEPEND ON
EXACTLY HOW THE SYSTEM EVOLVES BEYOND FRIDAY. ATTM SHOW WAVE HEIGHTS
LOWERING TO 3-5 FT SATURDAY AND THE CURRENT SCA ENDING AT 8AM
SATURDAY ACROSS THE SOUTHERN WATERS. NC SEAS WILL LIKELY REMAIN
ELEVATED BEYOND THE 8AM SCA END-TIME BUT WILL EXTEND AS NEEDED WITH
FUTURE UPDATES.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 330 AM THURSDAY...GUSTY WINDS TO START SUNDAY...ESPECIALLY
ACROSS THE NC WATERS...AS THE PERSISTENT LOW PRESSURE SYSTEM MOVES
SLOWLY NEAR THE AREA. ATTM THE BEST FORECAST TAKES THE LOW INLAND
ACROSS HORRY/BRUNSWICK COUNTIES...AND THUS WINDS THE FIRST HALF OF
SUNDAY WILL STILL BE GUSTY AROUND 20 KTS FROM THE EAST ACROSS
AMZ250/252...BUT MUCH WEAKER AND NORTHERLY OVER THE SC WATERS. THIS
SYSTEM WILL FINALLY BEGIN TO LIFT NE THROUGH SUNDAY AND INTO
MONDAY...SO WINDS WILL VEER TO THE SW AND BECOME 10-15 KTS ACROSS
ALL THE COASTAL WATERS. SEAS INITIALLY MAY STILL BE ABOVE SCA
THRESHOLDS ACROSS THE NC WATERS BUT SHOULD FALL THROUGH THE
DAY...AND 3-4 FT SEAS ARE FORECAST FOR MOST OF THE EXTENDED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT SATURDAY FOR AMZ250-252-
254-256.
&&
$$
SYNOPSIS...JDW
NEAR TERM...REK
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...DL
MARINE...REK/JDW
AREA FORECAST DISCUSSION
NWS BISMARCK ND
853 AM CDT THU MAY 7 2015
.UPDATE...
ISSUED AT 847 AM CDT THU MAY 7 2015
SHOWER ACTIVITY CONTINUES TO SLOWLY ERODE ON THE WEST
SIDE...THOUGH THIS IS OCCURRING A BIT SLOWER THAN PREVIOUS
FORECAST. THEREFORE...HAVE INCREASED POPS A BIT THROUGH MID DAY.
COLD FRONT HAS PUSHED THROUGH CENTRAL NORTH DAKOTA...AND IS SLOWLY
EXITING THE EASTERN JAMES RIVER VALLEY. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 533 AM CDT THU MAY 7 2015
SURFACE OBSERVATIONS PORTRAYING GUSTY NORTHWEST WINDS BETWEEN 25
AND 40 MPH BEHIND THE COLD FRONT. SURFACE COLD FRONT NOW MOVING
INTO JAMESTOWN AND SOUTH INTO OAKES.HAVE INCREASED WINDS CLOSER
TO THE 06Z MAV GUIDANCE THROUGH THE AFTERNOON. NEAR WIND ADVISORY
CRITERIA IN SOME SPOTS CURRENTLY...BUT WILL HOLD OFF AS UPSTREAM
WINDS IN SOUTHERN SASKATCHEWAN ARE MORE IN THE 20 TO 30 MPH RANGE.
LATEST RADAR AND WATER VAPOR IMAGERY DEPICT THE MID/UPPER LEVEL
LOW NOW CIRCULATING OVER THE SOUTHERN JAMES RIVER VALLEY. RADAR
RETURNS SLOWLY WEAKENING WEST OF BISMARCK AND THE CURRENT GRIDDED
FORECAST HAS THE POPS DIMINISHING FROM WEST TO EAST...WHICH IS ON
TRACK. BISMARCK ASOS TOTAL PRECIPITATION LAST 24HOURS HAS BEEN
0.72 INCHES.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 317 AM CDT THU MAY 7 2015
FOCUS IN THE SHORT TERM WILL BE ON EXITING SHOWERS AND THE
POTENTIAL FOR FROST THURSDAY NIGHT.
THE LATEST 00 UTC SOLUTIONS OF THE ECMWF AND GFS ARE IN GOOD
AGREEMENT ON PROGRESSING THE UPPER LEVEL SHORTWAVE AND UPPER LEVEL
LOW NORTHEAST OUT OF NORTH DAKOTA SHORTLY AFTER 18 UTC THURSDAY.
BEHIND THE UPPER LEVEL LOW THE LATEST 05 UTC RUN OF THE HRRR SHOWS
SHOWERS ACROSS CENTRAL NORTH DAKOTA BECOMING SCATTERED BY 16 UTC.
FOR THIS REASON HAVE HASTENED THE EXIT OF PRECIPITATION ACROSS
WESTERN AND CENTRAL NORTH DAKOTA. ALSO WITH OBSERVATIONS SHOWING
NOTHING IN THE WAY OF THUNDERSTORMS IN THE VICINITY OF NORTH
DAKOTA HAVE WENT AHEAD AND REMOVED ALL CHANCES FOR THUNDERSTORMS
THROUGH TODAY.
LOOKING AT THE FROST POTENTIAL FOR THURSDAY NIGHT THE BEST CHANCES
FOR FROST WILL BE WEST AND NORTH CENTRAL. MOS GUIDANCE FROM THE
GFS IS SHOWING THE LOWER 30S ACROSS THE NORTHWEST WHILE THE NAM
GUIDANCE IS SUGGESTING THE UPPER 20S. MODEL BLENDS ALSO HAVE SOME
LOW CLOUDS BUILDING BACK INTO WESTERN AND CENTRAL NORTH DAKOTA
WITH SOME MID LEVEL CLOUDS ALREADY IN PLACE. FOR NOW HAVE OPTED TO
GO WITH A MODEL BLEND FOR LOWS THURSDAY NIGHT WHICH SUGGEST A
POTENTIAL FOR FROST DEVELOPMENT ACROSS THE WEST AND PORTIONS OF
NORTH CENTRAL NORTH DAKOTA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 317 AM CDT THU MAY 7 2015
PATTERN CONTINUES TO EXHIBIT COOLER THAN NORMAL TEMPERATURES THROUGH
TUESDAY AS A POCKET OF COLDER AIR/850 TEMPERATURES HOVER BETWEEN 0C
AND -2C ACROSS WESTERN AND CENTRAL NORTH DAKOTA. A COUPLE OF
HIGHLIGHTS TO NOTE...LOWS IN THE 30S WILL LIKELY LEAD TO FROST
AND/OR FREEZE HEADLINES DURING THE LATE NIGHT/EARLY MORNING HOURS
THROUGH TUESDAY MORNING. THE SECOND HIGHLIGHT IS IN REGARDS TO
PRECIPITATION. THE MAIN THREAT STILL LOOKS TO OCCUR OVER SOUTHERN
AND EASTERN NORTH DAKOTA OVER THE WEEKEND INTO EARLY NEXT WEEK...AND
WITH THE COLDER AIR ALOFT AND COOLING AT NIGHT...EXPECT SOME SNOW
SHOWERS AT TIMES.
FRIDAY THROUGH THROUGH MONDAY NIGHT...ON FRIDAY A SURFACE HIGH WILL
SHIFT FROM SOUTH CENTRAL SASKATCHEWAN INTO MANITOBA WITH A
DRY/NORTHEAST FLOW ACROSS WESTERN AND CENTRAL NORTH DAKOTA. HIGHS
WILL BE IN THE 50S. BY FRIDAY NIGHT ATTENTION TURNS TOWARD THE NEXT
CLOSED UPPER LOW OVER THE FOUR CORNERS/SOUTHWEST CONUS AS IT BEGINS
TO EJECT EAST TO NORTHEAST INTO THE CENTRAL HIGH PLAINS SUNDAY INTO
MONDAY. SOME PHASING OCCURS BETWEEN THE NORTHERN/SOUTHERN STREAM
TROUGHS DURING THIS TIME. THE HIGHEST POPS REMAIN FOCUSED ACROSS
SOUTHERN NORTH DAKOTA SATURDAY/SATURDAY NIGHT...THEN PIVOTING INTO
SOUTH CENTRAL AND THE JAMES RIVER VALLEY SUNDAY THROUGH MONDAY. AS
MENTIONED ABOVE EXPECT SOME CHANCES FOR SNOW MIXING IN WITH THE RAIN
AT NIGHT/EARLY MORNING WITH LITTLE OR NO ACCUMULATIONS.
MONDAY NIGHT THROUGH WEDNESDAY...DRY WEATHER SLATED FOR MONDAY NIGHT
INTO WEDNESDAY. THE SUPERBLEND BEGINS TO SHOW A GRADUAL WARMING TREND
INTO THE LOWER 60S WEDNESDAY...AS 850MB TEMPERATURES WARM TO BETWEEN
+3C AND +5C. HOWEVER BOTH THE GFS AND ECMWF KEEP A CYCLONIC FLOW/SOME
TROUGHING OVER NORTH DAKOTA THROUGH THE MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 533 AM CDT THU MAY 7 2015
SURFACE LOW PRESSURE WAS CENTERED OVER THE EASTERN DAKOTAS AS OF 10Z
THURSDAY MORNING...WITH THE SURFACE FRONT JUST EAST OF KJMS. TIGHT
PRESSURE GRADIENT BEHIND THE LOW WILL PROVIDE SUSTAINED NORTHWEST
WINDS UP TO 20 KNOTS AND GUSTS TO 30 KNOTS THROUGH THE MORNING AND
AFTERNOON. SHOWERS WERE DISSIPATING ACROSS CENTRAL NORTH
DAKOTA...HOWEVER SHOWERS WILL BE POSSIBLE AT KBIS...KJMS...AND KMOT
THROUGH THE MORNING. CEILINGS WILL BE IN THE IFR TO MVFR CATEGORY
FOR MOST OF CENTRAL AND WESTERN NORTH DAKOTA THIS MORNING WITH
CEILINGS RISING FROM WEST TO EAST IN THE AFTERNOON AND NIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...MM
LONG TERM...KS
AVIATION...MM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
601 AM CDT THU MAY 7 2015
.UPDATE...
ISSUED AT 533 AM CDT THU MAY 7 2015
SURFACE OBSERVATIONS PORTRAYING GUSTY NORTHWEST WINDS BETWEEN 25
AND 40 MPH BEHIND THE COLD FRONT. SURFACE COLD FRONT NOW MOVING
INTO JAMESTOWN AND SOUTH INTO OAKES.HAVE INCREASED WINDS CLOSER
TO THE 06Z MAV GUIDANCE THROUGH THE AFTERNOON. NEAR WIND ADVISORY
CRITERIA IN SOME SPOTS CURRENTLY...BUT WILL HOLD OFF AS UPSTREAM
WINDS IN SOUTHERN SASKATCHEWAN ARE MORE IN THE 20 TO 30 MPH RANGE.
LATEST RADAR AND WATER VAPOR IMAGERY DEPICT THE MID/UPPER LEVEL
LOW NOW CIRCULATING OVER THE SOUTHERN JAMES RIVER VALLEY. RADAR
RETURNS SLOWLY WEAKENING WEST OF BISMARCK AND THE CURRENT GRIDDED
FORECAST HAS THE POPS DIMINISHING FROM WEST TO EAST...WHICH IS ON
TRACK. BISMARCK ASOS TOTAL PRECIPITATION LAST 24HOURS HAS BEEN
0.72 INCHES.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 317 AM CDT THU MAY 7 2015
FOCUS IN THE SHORT TERM WILL BE ON EXITING SHOWERS AND THE
POTENTIAL FOR FROST THURSDAY NIGHT.
THE LATEST 00 UTC SOLUTIONS OF THE ECMWF AND GFS ARE IN GOOD
AGREEMENT ON PROGRESSING THE UPPER LEVEL SHORTWAVE AND UPPER LEVEL
LOW NORTHEAST OUT OF NORTH DAKOTA SHORTLY AFTER 18 UTC THURSDAY.
BEHIND THE UPPER LEVEL LOW THE LATEST 05 UTC RUN OF THE HRRR SHOWS
SHOWERS ACROSS CENTRAL NORTH DAKOTA BECOMING SCATTERED BY 16 UTC.
FOR THIS REASON HAVE HASTENED THE EXIT OF PRECIPITATION ACROSS
WESTERN AND CENTRAL NORTH DAKOTA. ALSO WITH OBSERVATIONS SHOWING
NOTHING IN THE WAY OF THUNDERSTORMS IN THE VICINITY OF NORTH
DAKOTA HAVE WENT AHEAD AND REMOVED ALL CHANCES FOR THUNDERSTORMS
THROUGH TODAY.
LOOKING AT THE FROST POTENTIAL FOR THURSDAY NIGHT THE BEST CHANCES
FOR FROST WILL BE WEST AND NORTH CENTRAL. MOS GUIDANCE FROM THE
GFS IS SHOWING THE LOWER 30S ACROSS THE NORTHWEST WHILE THE NAM
GUIDANCE IS SUGGESTING THE UPPER 20S. MODEL BLENDS ALSO HAVE SOME
LOW CLOUDS BUILDING BACK INTO WESTERN AND CENTRAL NORTH DAKOTA
WITH SOME MID LEVEL CLOUDS ALREADY IN PLACE. FOR NOW HAVE OPTED TO
GO WITH A MODEL BLEND FOR LOWS THURSDAY NIGHT WHICH SUGGEST A
POTENTIAL FOR FROST DEVELOPMENT ACROSS THE WEST AND PORTIONS OF
NORTH CENTRAL NORTH DAKOTA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 317 AM CDT THU MAY 7 2015
PATTERN CONTINUES TO EXHIBIT COOLER THAN NORMAL TEMPERATURES THROUGH
TUESDAY AS A POCKET OF COLDER AIR/850 TEMPERATURES HOVER BETWEEN 0C
AND -2C ACROSS WESTERN AND CENTRAL NORTH DAKOTA. A COUPLE OF
HIGHLIGHTS TO NOTE...LOWS IN THE 30S WILL LIKELY LEAD TO FROST
AND/OR FREEZE HEADLINES DURING THE LATE NIGHT/EARLY MORNING HOURS
THROUGH TUESDAY MORNING. THE SECOND HIGHLIGHT IS IN REGARDS TO
PRECIPITATION. THE MAIN THREAT STILL LOOKS TO OCCUR OVER SOUTHERN
AND EASTERN NORTH DAKOTA OVER THE WEEKEND INTO EARLY NEXT WEEK...AND
WITH THE COLDER AIR ALOFT AND COOLING AT NIGHT...EXPECT SOME SNOW
SHOWERS AT TIMES.
FRIDAY THROUGH THROUGH MONDAY NIGHT...ON FRIDAY A SURFACE HIGH WILL
SHIFT FROM SOUTH CENTRAL SASKATCHEWAN INTO MANITOBA WITH A
DRY/NORTHEAST FLOW ACROSS WESTERN AND CENTRAL NORTH DAKOTA. HIGHS
WILL BE IN THE 50S. BY FRIDAY NIGHT ATTENTION TURNS TOWARD THE NEXT
CLOSED UPPER LOW OVER THE FOUR CORNERS/SOUTHWEST CONUS AS IT BEGINS
TO EJECT EAST TO NORTHEAST INTO THE CENTRAL HIGH PLAINS SUNDAY INTO
MONDAY. SOME PHASING OCCURS BETWEEN THE NORTHERN/SOUTHERN STREAM
TROUGHS DURING THIS TIME. THE HIGHEST POPS REMAIN FOCUSED ACROSS
SOUTHERN NORTH DAKOTA SATURDAY/SATURDAY NIGHT...THEN PIVOTING INTO
SOUTH CENTRAL AND THE JAMES RIVER VALLEY SUNDAY THROUGH MONDAY. AS
MENTIONED ABOVE EXPECT SOME CHANCES FOR SNOW MIXING IN WITH THE RAIN
AT NIGHT/EARLY MORNING WITH LITTLE OR NO ACCUMULATIONS.
MONDAY NIGHT THROUGH WEDNESDAY...DRY WEATHER SLATED FOR MONDAY NIGHT
INTO WEDNESDAY. THE SUPERBLEND BEGINS TO SHOW A GRADUAL WARMING TREND
INTO THE LOWER 60S WEDNESDAY...AS 850MB TEMPERATURES WARM TO BETWEEN
+3C AND +5C. HOWEVER BOTH THE GFS AND ECMWF KEEP A CYCLONIC FLOW/SOME
TROUGHING OVER NORTH DAKOTA THROUGH THE MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 533 AM CDT THU MAY 7 2015
SURFACE LOW PRESSURE WAS CENTERED OVER THE EASTERN DAKOTAS AS OF 10Z
THURSDAY MORNING...WITH THE SURFACE FRONT JUST EAST OF KJMS. TIGHT
PRESSURE GRADIENT BEHIND THE LOW WILL PROVIDE SUSTAINED NORTHWEST
WINDS UP TO 20 KNOTS AND GUSTS TO 30 KNOTS THROUGH THE MORNING AND
AFTERNOON. SHOWERS WERE DISSIPATING ACROSS CENTRAL NORTH
DAKOTA...HOWEVER SHOWERS WILL BE POSSIBLE AT KBIS...KJMS...AND KMOT
THROUGH THE MORNING. CEILINGS WILL BE IN THE IFR TO MVFR CATEGORY
FOR MOST OF CENTRAL AND WESTERN NORTH DAKOTA THIS MORNING WITH
CEILINGS RISING FROM WEST TO EAST IN THE AFTERNOON AND NIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...MM
LONG TERM...KS
AVIATION...MM
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
1042 AM EDT THU MAY 7 2015
.DISCUSSION...
LITTLE CHANGE IN THE WEATHER PATTERN OVER THE PAST 24 HOURS SHOULD
RESULT IN TODAY BEING VERY SIMILAR TO YESTERDAY. 12Z RAOBS AROUND
THE REGION SHOW 850 MB TEMPS BEING A DEGREE OR SO ABOVE
YESTERDAY...SO HIGHS TEMPS TODAY SHOULD BE IN THE MID 80S IN THE
VALLEY...WITH A FEW SPOTS TOUCHING THE UPPER 80S. THIS WILL
NECESSITATE A SLIGHT UPWARD ADJUSTMENT IN FORECAST TEMPS. SCATTERED
AFTERNOON SHOWERS ARE EXPECTED IN THE HIGHER TERRAIN AND SW
VA...WITH MOVEMENT TOWARD THE W-SW THAT MAY BRING A FEW OF THEM
INTO THE VALELY BEFORE DISSIPATING. THE HRRR HAD A GOOD HANDLE ON
THIS YESTERDAY...AND WILL BE FOLLOWED AGAIN TODAY. SOME EXPANSION
OF SLIGHT CHANCE POPS WILL BE MADE INTO THE VALLEY WITH THE UPDATE.
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1017 AM CDT THU MAY 7 2015
.UPDATE...
QUICK UPDATE TO INCREASE POPS FOR THE REMAINDER OF THE MORNING. AN
UPPER LEVEL SHORT WAVE TROUGH LIFTING NEWD ACROSS SERN NM ACTING
ON ELEVATED INSTABILITY HELPING KICK OFF SCATTERED TO NUMEROUS
THUNDERSTORMS. THIS TROUGH IS EXPECTED TO EXIT THE REGION BY MID
AFTERNOON AND ITS EGRESS COULD HAVE A NEGATIVE EFFECT ON
CONVECTIVE INITIATION LATER THIS AFTERNOON GIVEN EXPECTATION OF
SOME DOWNWARD MOTION IN ITS WAKE AND THE RELEASE OF POTENTIAL
ENERGY THIS MORNING WITH THIS ROUND OF STORMS. WILL KEEP POST-18Z
POPS ALONE ATTM WITH THE WEST TO EAST GRADIENT LOOKING FINE AS
SOME SHOWERS AND STORMS LIKELY TO LINGER PAST 18Z. NO OTHER
CHANGES MADE ATTM.
&&
.PREV DISCUSSION... /ISSUED 647 AM CDT THU MAY 7 2015/
AVIATION...
MVFR TO IFR CONDITIONS IN PLACE AT ALL THREE TAF SITES ONCE AGAIN
THIS MORNING. EXPECT TO SEE A GRADUAL TRANSITION TO VFR BY LATE
THIS MORNING AS CEILINGS START TO LIFT. THERE COULD BE SHOWERS AND
THUNDERSTORMS LATE THIS MORNING THROUGH THIS EVENING WITH THE
GREATEST CHANCES AT KCDS. STORMS COULD DEVELOP AS FAR WEST AS KLBB
AND KPVW BUT CONFIDENCE WAS NOT HIGH ENOUGH TO INCLUDE IN THE TAFS
AT THIS TIME. WILL HAVE TO EVALUATE THROUGH THE DAY FOR POSSIBLE
INCLUSION IN LATER TAF ISSUANCES. ANY STORMS THAT DEVELOP WILL
MOVE AWAY FROM THE TAF SITES AFTER 06Z TOMORROW BUT WE COULD SEE
ANOTHER ROUND OF MVFR TO IFR CONDITIONS TOMORROW MORNING.
JORDAN
PREV DISCUSSION... /ISSUED 351 AM CDT THU MAY 7 2015/
SHORT TERM...
JUST AS WE SAW LAST NIGHT...STORMS MOVED OUT OF THE AREA OR WEAKENED
JUST AFTER MIDNIGHT LOCAL TIME AND THE DRYLINE CONTINUES TO SLOSH
BACK TO THE WEST. ONE DIFFERENCE IS THAT THERE IS A SUBTLE
SHORTWAVE OVER SOUTHEAST NEW MEXICO THAT IS TRYING TO GENERATE SOME
SHOWERS AS IT APPROACHES THE REGION. THIS SHORTWAVE MAY COMPLICATE
MATTERS FOR THIS AFTERNOON IF PRECIPITATION CAN DEVELOP AND BECOME
MORE EXPANSIVE ACROSS THE FORECAST AREA. THE RAP AND HRRR AND TO
SOME EXTENT THE NAM ARE TRYING TO DEVELOP AN AREA OF PRECIPITATION
ACROSS THE SOUTHWESTERN SOUTH PLAINS AND SOUTHEASTERN NEW MEXICO
THAT SPREADS NORTHEAST BEFORE SUNRISE. AMPLE LOW LEVEL MOISTURE
WILL BE IN PLACE TO THE EAST OF THE DRYLINE AS INDICATED BY LOW
CLOUDS AND PATCHY FOG ONCE AGAIN DEVELOPING ACROSS THE ROLLING
PLAINS AND STARTING TO SPREAD OVER THE CAPROCK. PULLED POPS BACK TO
THE WEST FOR THIS MORNING BUT KEPT THEM BARELY IN THE SLIGHT CHANCE
RANGE.
STORM CHANCES FOR THIS AFTERNOON WILL ONCE AGAIN DEPEND ON WHERE THE
DRYLINE MIXES TO AND IF ANY OTHER WEAK SHORTWAVES WILL MOVE ACROSS
THE AREA TO PROVIDE SOME WEAK LIFT TO INITIATE STORMS. FORECAST
SOUNDINGS STILL SHOW A BIT OF A WEAK CAP OVER THE AREA THIS MORNING
BUT THIS COULD EASILY BE OVERCOME BY DAYTIME HEATING. MLCAPE VALUES
WILL ONCE AGAIN CLIMB INTO THE 2000-3000 J/KG SO THERE WILL BE
PLENTY OF ENERGY FOR STORMS TO ACCESS. WIND PROFILES SHOW A BIT OF
A WEAKNESS BETWEEN 850 AND 700 HPA WHICH MAY IMPACT STORM MORPHOLOGY
BUT AMOUNT OF INSTABILITY AND DECENT VENTILATION ALOFT POINTS
TOWARDS THE POSSIBILITY OF SUPERCELLS WITH LARGE HAIL THE PREDOMINANT
THREAT. HOWEVER...RADAR LOOP SHOWS THAT THERE IS A POSSIBLE OUTFLOW
BOUNDARY FROM THE STORMS OVER OKLAHOMA/NORTH TEXAS THAT IS PUSHING
WEST. ADD IN BOUNDARIES LEFT OVER FROM ANY STORMS THAT MAY OR MAY
NOT DEVELOP THIS MORNING AND THERE COULD BE SOME LOCALIZED THREAT
FOR TORNADO DEVELOPMENT ALONG THESE BOUNDARIES. UNFORTUNATELY IT
IS TOO HARD TO TELL RIGHT NOW IF THERE WILL BE ANY ONE AREA OVER
ANOTHER THAT HAS A GREATER THREAT FOR TORNADOES.
TEMPERATURES WILL BE FAIRLY CLOSE TO WHAT WE SAW YESTERDAY FOR BOTH
MIN AND MAX TEMPS. AS MENTIONED EARLIER...DID INCREASE POPS THIS
MORNING AND ALSO INCREASED POPS ACROSS THE ROLLING PLAINS FOR THIS
AFTERNOON. PUT MENTION OF SEVERE IN FOR THE EASTERN TWO THIRDS OF
THE FORECAST AREA FOR THIS AFTERNOON AND EARLY EVENING BUT TAPERED
POPS OFF AFTER MIDNIGHT A BIT FOLLOWING THE DIURNAL CYCLE WE HAVE
SEEN THE LAST SEVERAL DAYS.
JORDAN
LONG TERM...
LITTLE CHANGE TO THE EXTENDED FORECAST WITH THE PRIMARY FOCUS ON THE
ACTIVE EARLY MAY WEATHER THAT WILL PERSIST IN THE REGION INTO
SATURDAY.
THE UPPER LOW CURRENTLY DIGGING SOUTHWARD ACROSS THE WESTERN STATES
WILL BE CENTERED OVER SOUTHERN CA/NV TO KICK OF THE EXTENDED FRIDAY.
THERE IS GOOD AGREEMENT THAT THE LOW WILL MOVE STEADILY EASTWARD TO
NEAR THE FOUR CORNERS AROUND MIDDAY SATURDAY BEFORE EMERGING OVER
THE CENTRAL HIGH PLAINS ON SUNDAY. THIS TRACK WILL KEEP WEST TEXAS
UNDER STRENGTHENING SOUTHWESTERLY FLOW ALOFT WHILE RICH MOISTURE
ALREADY ENCOMPASSING MUCH OF THE LONE STAR STATE DOES NOT GO
ANYWHERE. VERY STEEP MID-LEVEL LAPSES ATOP THE RICH AND MOIST
BOUNDARY LAYER EAST OF THE DRYLINE WILL RESULT IN STRONG INSTABILITY
EVERY DAY...THOUGH ANY EARLY DAY CONVECTION AND CLOUD COVER WILL
DICTATE WHERE THE MOST VOLATILE AIR WILL RESIDE ON ANY PARTICULAR
AFTERNOON/EVENING. THE ABOVE FACTORS WILL WILL SET THE STAGE FOR
ROBUST MOIST CONVECTION ALONG AND EAST OF THE DRYLINE THE NEXT FEW
DAYS...WITH ALL FORMS OF SEVERE WEATHER /VERY LARGE HAIL...DAMAGING
WINDS AND ISOLATED TORNADOES/ POSSIBLE IN ADDITION TO LOCALLY HEAVY
RAIN.
CONVECTION COULD START FAIRLY EARLY ON FRIDAY AS ANOTHER SUBTLE
SHORTWAVE TROUGH IS PROGGED TO ROTATE AROUND THE UPPER LOW AND
APPROACH THE SOUTH PLAINS REGION BY MIDDAY OR SO. RECENT NWP SUGGEST
THE DRYLINE WILL BE POSITIONED SOMEWHERE NEAR THE EDGE OF THE
CAPROCK TOMORROW AFTERNOON...SO THE HIGHEST SEVERE WEATHER
PROBABILITIES WILL BE ALONG AND EAST OF THIS LINE FRIDAY
AFTERNOON/EVENING...THOUGH LOCATIONS FURTHER WEST COULD SEE
CONVECTION EARLY IN THE DAY. THE DRYLINE SHOULD QUICKLY RETREAT
FRIDAY NIGHT AS THE FLOW BACKS IN RESPONSE TO THE APPROACHING UPPER
LOW. IT APPEARS THE MOISTURE COULD MAKE IT ALL THE WAY BACK TO
THE TX/NM LINE FOR A SHORT TIME EARLY SATURDAY BEFORE
STRENGTHENING LOW-LEVEL SOUTHWESTERLY FLOW SHUNTS THE MOISTURE
BACK EASTWARD. ALTHOUGH NWP SIGNALS ARE MIXED...WE WOULD EXPECT
CONVECTION TO ERUPT ALONG THE DRYLINE EARLY SATURDAY AS THE
STRONGEST UPPER LIFT GRAZES THE AREA. THE DRYLINE AND EARLY DAY
CONVECTION SHOULD THEN RACE EASTWARD AS THE DRIER SOUTHWEST WINDS
SPREAD FROM WEST TO EAST ACROSS THE FA. THE DRYLINE MAY MAKE IT
ALL THE WAY TO OR EVEN SLIGHTLY EAST OF THE CWA BY SATURDAY
EVENING...THOUGH WE HAVE MAINTAINED SLIM POPS ACROSS THE FAR
EASTERN ZONES GIVEN THE UNCERTAINTY. WEST OF THE DRYLINE BREEZY TO
LOW-END WINDY CONDITION WILL ENVELOP THE CAPROCK SATURDAY
AFTERNOON WHILE TEMPERATURES PEAK NEAR EARLY MAY AVERAGES.
THE DRY WESTERLY FLOW WILL PERSIST OVER MUCH OF THE AREA SUNDAY WITH
MODEST COOLING AS THE UPPER TROUGH AXIS APPROACHES FROM THE WEST.
THE ONE EXCEPTION COULD BE THE FAR SOUTHEAST ZONES AROUND ASPERMONT
WHERE THE LOW-LEVEL MOISTURE MAY LINGER NEARBY AND PROVIDE AT LEAST
A LOW RISK OF A STORM.
A COLD FRONT WILL FOLLOW THE TROUGH PASSAGE EARLY MONDAY PROVIDING
BELOW AVERAGE TEMPERATURES AND DRY CONDITIONS TO BEGIN NEXT WEEK.
MOISTURE WILL GRADUALLY RETURN THEREAFTER AND WE COULD SEE THE UPPER
RIDGE EARLY IN THE WEEK BEGIN TO BREAKDOWN AND PROVIDE A RETURN OF
LOW THUNDER CHANCES TO THE FORECAST TOWARD MIDWEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 78 49 80 48 / 40 20 10 20
TULIA 79 54 81 54 / 70 20 30 40
PLAINVIEW 79 55 81 54 / 70 30 30 40
LEVELLAND 82 56 83 56 / 50 30 20 50
LUBBOCK 80 58 84 58 / 50 30 30 40
DENVER CITY 82 54 83 53 / 40 20 20 50
BROWNFIELD 83 56 85 57 / 50 30 30 50
CHILDRESS 82 61 84 64 / 70 40 50 40
SPUR 81 57 84 63 / 50 40 50 40
ASPERMONT 84 61 86 66 / 50 40 50 40
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07/99
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
647 AM CDT THU MAY 7 2015
.AVIATION...
MVFR TO IFR CONDITIONS IN PLACE AT ALL THREE TAF SITES ONCE AGAIN
THIS MORNING. EXPECT TO SEE A GRADUAL TRANSITION TO VFR BY LATE
THIS MORNING AS CEILINGS START TO LIFT. THERE COULD BE SHOWERS AND
THUNDERSTORMS LATE THIS MORNING THROUGH THIS EVENING WITH THE
GREATEST CHANCES AT KCDS. STORMS COULD DEVELOP AS FAR WEST AS KLBB
AND KPVW BUT CONFIDENCE WAS NOT HIGH ENOUGH TO INCLUDE IN THE TAFS
AT THIS TIME. WILL HAVE TO EVALUATE THROUGH THE DAY FOR POSSIBLE
INCLUSION IN LATER TAF ISSUANCES. ANY STORMS THAT DEVELOP WILL
MOVE AWAY FROM THE TAF SITES AFTER 06Z TOMORROW BUT WE COULD SEE
ANOTHER ROUND OF MVFR TO IFR CONDITIONS TOMORROW MORNING.
JORDAN
&&
.PREV DISCUSSION... /ISSUED 351 AM CDT THU MAY 7 2015/
SHORT TERM...
JUST AS WE SAW LAST NIGHT...STORMS MOVED OUT OF THE AREA OR WEAKENED
JUST AFTER MIDNIGHT LOCAL TIME AND THE DRYLINE CONTINUES TO SLOSH
BACK TO THE WEST. ONE DIFFERENCE IS THAT THERE IS A SUBTLE
SHORTWAVE OVER SOUTHEAST NEW MEXICO THAT IS TRYING TO GENERATE SOME
SHOWERS AS IT APPROACHES THE REGION. THIS SHORTWAVE MAY COMPLICATE
MATTERS FOR THIS AFTERNOON IF PRECIPITATION CAN DEVELOP AND BECOME
MORE EXPANSIVE ACROSS THE FORECAST AREA. THE RAP AND HRRR AND TO
SOME EXTENT THE NAM ARE TRYING TO DEVELOP AN AREA OF PRECIPITATION
ACROSS THE SOUTHWESTERN SOUTH PLAINS AND SOUTHEASTERN NEW MEXICO
THAT SPREADS NORTHEAST BEFORE SUNRISE. AMPLE LOW LEVEL MOISTURE
WILL BE IN PLACE TO THE EAST OF THE DRYLINE AS INDICATED BY LOW
CLOUDS AND PATCHY FOG ONCE AGAIN DEVELOPING ACROSS THE ROLLING
PLAINS AND STARTING TO SPREAD OVER THE CAPROCK. PULLED POPS BACK TO
THE WEST FOR THIS MORNING BUT KEPT THEM BARELY IN THE SLIGHT CHANCE
RANGE.
STORM CHANCES FOR THIS AFTERNOON WILL ONCE AGAIN DEPEND ON WHERE THE
DRYLINE MIXES TO AND IF ANY OTHER WEAK SHORTWAVES WILL MOVE ACROSS
THE AREA TO PROVIDE SOME WEAK LIFT TO INITIATE STORMS. FORECAST
SOUNDINGS STILL SHOW A BIT OF A WEAK CAP OVER THE AREA THIS MORNING
BUT THIS COULD EASILY BE OVERCOME BY DAYTIME HEATING. MLCAPE VALUES
WILL ONCE AGAIN CLIMB INTO THE 2000-3000 J/KG SO THERE WILL BE
PLENTY OF ENERGY FOR STORMS TO ACCESS. WIND PROFILES SHOW A BIT OF
A WEAKNESS BETWEEN 850 AND 700 HPA WHICH MAY IMPACT STORM MORPHOLOGY
BUT AMOUNT OF INSTABILITY AND DECENT VENTILATION ALOFT POINTS
TOWARDS THE POSSIBILITY OF SUPERCELLS WITH LARGE HAIL THE PREDOMINANT
THREAT. HOWEVER...RADAR LOOP SHOWS THAT THERE IS A POSSIBLE OUTFLOW
BOUNDARY FROM THE STORMS OVER OKLAHOMA/NORTH TEXAS THAT IS PUSHING
WEST. ADD IN BOUNDARIES LEFT OVER FROM ANY STORMS THAT MAY OR MAY
NOT DEVELOP THIS MORNING AND THERE COULD BE SOME LOCALIZED THREAT
FOR TORNADO DEVELOPMENT ALONG THESE BOUNDARIES. UNFORTUNATELY IT
IS TOO HARD TO TELL RIGHT NOW IF THERE WILL BE ANY ONE AREA OVER
ANOTHER THAT HAS A GREATER THREAT FOR TORNADOES.
TEMPERATURES WILL BE FAIRLY CLOSE TO WHAT WE SAW YESTERDAY FOR BOTH
MIN AND MAX TEMPS. AS MENTIONED EARLIER...DID INCREASE POPS THIS
MORNING AND ALSO INCREASED POPS ACROSS THE ROLLING PLAINS FOR THIS
AFTERNOON. PUT MENTION OF SEVERE IN FOR THE EASTERN TWO THIRDS OF
THE FORECAST AREA FOR THIS AFTERNOON AND EARLY EVENING BUT TAPERED
POPS OFF AFTER MIDNIGHT A BIT FOLLOWING THE DIURNAL CYCLE WE HAVE
SEEN THE LAST SEVERAL DAYS.
JORDAN
LONG TERM...
LITTLE CHANGE TO THE EXTENDED FORECAST WITH THE PRIMARY FOCUS ON THE
ACTIVE EARLY MAY WEATHER THAT WILL PERSIST IN THE REGION INTO
SATURDAY.
THE UPPER LOW CURRENTLY DIGGING SOUTHWARD ACROSS THE WESTERN STATES
WILL BE CENTERED OVER SOUTHERN CA/NV TO KICK OF THE EXTENDED FRIDAY.
THERE IS GOOD AGREEMENT THAT THE LOW WILL MOVE STEADILY EASTWARD TO
NEAR THE FOUR CORNERS AROUND MIDDAY SATURDAY BEFORE EMERGING OVER
THE CENTRAL HIGH PLAINS ON SUNDAY. THIS TRACK WILL KEEP WEST TEXAS
UNDER STRENGTHENING SOUTHWESTERLY FLOW ALOFT WHILE RICH MOISTURE
ALREADY ENCOMPASSING MUCH OF THE LONE STAR STATE DOES NOT GO
ANYWHERE. VERY STEEP MID-LEVEL LAPSES ATOP THE RICH AND MOIST
BOUNDARY LAYER EAST OF THE DRYLINE WILL RESULT IN STRONG INSTABILITY
EVERY DAY...THOUGH ANY EARLY DAY CONVECTION AND CLOUD COVER WILL
DICTATE WHERE THE MOST VOLATILE AIR WILL RESIDE ON ANY PARTICULAR
AFTERNOON/EVENING. THE ABOVE FACTORS WILL WILL SET THE STAGE FOR
ROBUST MOIST CONVECTION ALONG AND EAST OF THE DRYLINE THE NEXT FEW
DAYS...WITH ALL FORMS OF SEVERE WEATHER /VERY LARGE HAIL...DAMAGING
WINDS AND ISOLATED TORNADOES/ POSSIBLE IN ADDITION TO LOCALLY HEAVY
RAIN.
CONVECTION COULD START FAIRLY EARLY ON FRIDAY AS ANOTHER SUBTLE
SHORTWAVE TROUGH IS PROGGED TO ROTATE AROUND THE UPPER LOW AND
APPROACH THE SOUTH PLAINS REGION BY MIDDAY OR SO. RECENT NWP SUGGEST
THE DRYLINE WILL BE POSITIONED SOMEWHERE NEAR THE EDGE OF THE
CAPROCK TOMORROW AFTERNOON...SO THE HIGHEST SEVERE WEATHER
PROBABILITIES WILL BE ALONG AND EAST OF THIS LINE FRIDAY
AFTERNOON/EVENING...THOUGH LOCATIONS FURTHER WEST COULD SEE
CONVECTION EARLY IN THE DAY. THE DRYLINE SHOULD QUICKLY RETREAT
FRIDAY NIGHT AS THE FLOW BACKS IN RESPONSE TO THE APPROACHING UPPER
LOW. IT APPEARS THE MOISTURE COULD MAKE IT ALL THE WAY BACK TO
THE TX/NM LINE FOR A SHORT TIME EARLY SATURDAY BEFORE
STRENGTHENING LOW-LEVEL SOUTHWESTERLY FLOW SHUNTS THE MOISTURE
BACK EASTWARD. ALTHOUGH NWP SIGNALS ARE MIXED...WE WOULD EXPECT
CONVECTION TO ERUPT ALONG THE DRYLINE EARLY SATURDAY AS THE
STRONGEST UPPER LIFT GRAZES THE AREA. THE DRYLINE AND EARLY DAY
CONVECTION SHOULD THEN RACE EASTWARD AS THE DRIER SOUTHWEST WINDS
SPREAD FROM WEST TO EAST ACROSS THE FA. THE DRYLINE MAY MAKE IT
ALL THE WAY TO OR EVEN SLIGHTLY EAST OF THE CWA BY SATURDAY
EVENING...THOUGH WE HAVE MAINTAINED SLIM POPS ACROSS THE FAR
EASTERN ZONES GIVEN THE UNCERTAINTY. WEST OF THE DRYLINE BREEZY TO
LOW-END WINDY CONDITION WILL ENVELOP THE CAPROCK SATURDAY
AFTERNOON WHILE TEMPERATURES PEAK NEAR EARLY MAY AVERAGES.
THE DRY WESTERLY FLOW WILL PERSIST OVER MUCH OF THE AREA SUNDAY WITH
MODEST COOLING AS THE UPPER TROUGH AXIS APPROACHES FROM THE WEST.
THE ONE EXCEPTION COULD BE THE FAR SOUTHEAST ZONES AROUND ASPERMONT
WHERE THE LOW-LEVEL MOISTURE MAY LINGER NEARBY AND PROVIDE AT LEAST
A LOW RISK OF A STORM.
A COLD FRONT WILL FOLLOW THE TROUGH PASSAGE EARLY MONDAY PROVIDING
BELOW AVERAGE TEMPERATURES AND DRY CONDITIONS TO BEGIN NEXT WEEK.
MOISTURE WILL GRADUALLY RETURN THEREAFTER AND WE COULD SEE THE UPPER
RIDGE EARLY IN THE WEEK BEGIN TO BREAKDOWN AND PROVIDE A RETURN OF
LOW THUNDER CHANCES TO THE FORECAST TOWARD MIDWEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 78 49 80 48 / 20 20 10 20
TULIA 79 54 81 54 / 30 20 30 40
PLAINVIEW 79 55 81 54 / 30 30 30 40
LEVELLAND 82 56 83 56 / 20 30 20 50
LUBBOCK 80 58 84 58 / 30 30 30 40
DENVER CITY 82 54 83 53 / 20 20 20 50
BROWNFIELD 83 56 85 57 / 30 30 30 50
CHILDRESS 82 61 84 64 / 50 40 50 40
SPUR 81 57 84 63 / 50 40 50 40
ASPERMONT 84 61 86 66 / 50 40 50 40
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
535 AM CDT THU MAY 7 2015
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...LOW MVFR CIGS ARE OCCURRING ACROSS ALL OF DEEP SOUTH
TEXAS. MUCH LIKE THE PAST SEVERAL DAYS...LOW MVFR WILL SLOWLY
RISE THROUGH THE MORNING HOURS THAT BECOMING LOW VFR THIS
AFTERNOON. SFC FEATURES HAVE NOT CHANGED MUCH WHICH WILL LEAD TO
ANOTHER BREEZY DAYS WITH GUSTS TO 25 KNOTS POSSIBLE THIS
AFTERNOON. WINDS WILL DECREASE AFTER SUNSET WITH CIGS LOWERING TO
MVFR THIS EVENING THEN PERHAPS IFR OVERNIGHT.
&&
.PREV DISCUSSION... /ISSUED 328 AM CDT THU MAY 7 2015/
SHORT TERM /NOW THROUGH FRIDAY/...H5 TROF WILL SLIDE SOUTHWARD
ACROSS CALIFORNIA AND INTO THE DESERT SOUTHWEST. MID LEVEL RIDGE
WILL BE DRAPED ACROSS THE WESTERN GULF OF MEXICO AND A S/W TROUGH
OFF THE FLORIDA COAST. PERSISTENT SOUTHEASTERLY FLOW WILL CONTINUE
WITH SFC HIGH PRESSURE ACROSS THE NORTHEASTERN GULF OF MEXICO AND
LOW PRESSURE ACROSS THE HIGH PLAINS. BREEZY CONDITIONS WILL
CONTINUE THROUGH THE SHORT TERM PERIOD WITH GUSTS TO 25-30 MPH
POSSIBLE IN THE AFTERNOON HOURS. 850-700MB TEMPERATURES WARM
THROUGH THE PERIOD SO AN INCREASE AN AFTERNOON HIGHS UP INTO THE
LOWER 90S MIDDLE/UPPER VALLEY WITH UPPER 80S IN THE LOWER VALLEY
EACH DAY.
FOR PRECIPITATION CHANCES...HAVE SLIGHT CHANCE POPS THIS MORNING FOR
ANY ISOLATED SHOWER THAT HAPPENS TO DEVELOP UNDERNEATH THE STRONG
INVERSION /MUCH LIKE THE PAST SEVERAL DAYS/. MODELS ONCE AGAIN
PROG A WEAK DISTURBANCE MOVING ACROSS THE HIGHER TERRAIN THIS
AFTERNOON AND EVENING. HRRR AND GFS DEVELOP THUNDERSTORMS OVER THE
SIERRA MADRES THIS AFTERNOON AND MOVE EAST TOWARDS THE UPPER
VALLEY. WILL MAINTAIN SLIGHT CHANCE POPS OUT WEST THIS EVENING
THEN DECREASE OVERNIGHT AS CIN INCREASES RAPIDLY.
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...THE APPROACH AND
PASSAGE OF A 500 MB TROUGH THROUGH THE TEXAS BIG BEND WILL ONCE
AGAIN INITIATE THUNDERSTORMS OVER THE NEIGHBORING HIGH TERRAIN OF
MEXICO...AND SOME OF THIS ACTIVITY MAY AFFECT THE BRO CWFA...
ESPECIALLY THE WESTERN THIRD AND NORTHERN HALF OF THE REGION.
STORM PREDICTION CENTER HAS A MARGINAL TO ENHANCED RISK OF SEVERE
WEATHER FOR MUCH OF TEXAS NORTH OF THE RIO GRANDE VALLEY AND DEEP
SOUTH TEXAS...SO SUCCESSIVE SHIFTS WILL HAVE TO MONITOR FOR THE
POSSIBILITY THAT SOME OF THIS STRONG TO SEVERE THUNDERSTORM
ACTIVITY MAY SNEAK INTO THE BRO CWFA FRIDAY NIGHT. AFTERWARDS...DRY
WEATHER WILL PREVAIL UNTIL ANOTHER POSSIBLE ROUND OF THUNDERSTORMS
OUT WEST SUNDAY NIGHT. A GREATLY ENHANCED OPPORTUNITY FOR RAINFALL
IS ANTICIPATED MONDAY THROUGH WEDNESDAY DUE TO THE INTRUSION AND
STALLING OF A WEAK COLD FRONT...A SOUTHWEST-TO-NORTHEAST 500 MB
FLOW OVERHEAD...AND THE FORMATION AND PERSISTENCE OF A SURFACE
TROUGH OF LOW PRESSURE WITHIN THE BRO CWFA. WITH DEEP TROPICAL
MOISTURE EXPECTED TO ALSO BE IN PLACE...WITH PRECIPITABLE WATER
VALUES AROUND 2 INCHES...THE POTENTIAL FOR LOCALLY HEAVY AND
FLOODING RAINFALL MAY EXIST MONDAY THROUGH WEDNESDAY. HOWEVER
..HAVE NOT INCLUDED THIS IN THE UPCOMING FORECAST AND WILL KEEP
AN EYE ON THE POTENTIAL FOR THIS HEAVY/FLOODING RAINFALL THROUGH
THE NEXT SEVERAL DAYS. NO MAJOR SURPRISES FOR THE TEMPERATURES...
NEAR TO SLIGHTLY ABOVE NORMAL THROUGHOUT THE ENTIRE LONG TERM
FORECAST PERIOD.
MARINE...NOW THROUGH FRIDAY...SEAS WERE NEAR 5 FEET WITH SOUTHEAST
WINDS NEAR 16 KNOTS AT BUOY020 THIS MORNING. MODERATE TO STRONG
SOUTHEAST WINDS WILL PREVAIL ACROSS THE COASTAL WATERS TODAY AS
THE PRESSURE GRADIENT REMAINS STRONG ACROSS THE WESTERN GULF OF
MEXICO. WILL HAVE SCEC ACROSS ALL LOWER TEXAS COASTAL WATERS TODAY
AND GULF WATERS TONIGHT. FOR FRIDAY SCEC WILL BE NEEDED ACROSS ALL
LOWER TEXAS COASTAL WATERS ONCE AGAIN.
FRIDAY NIGHT THROUGH WEDNESDAY...SURFACE HIGH PRESSURE CENTERED
JUST SOUTH OF THE FLORIDA PENINSULA WILL INTERACT WITH PERSISTENT
LOW PRESSURE OVER THE CENTRAL PLAINS FROM FRIDAY NIGHT THROUGH
THE WEEKEND...PRODUCING SMALL CRAFT ADVISORY WINDS/SEAS ALONG THE
LOWER TEXAS COAST THROUGH THIS PERIOD. ALTHOUGH HIGH PRESSURE WILL
BECOME MORE IN CONTROL OVER THE WESTERN GULF OF MEXICO AFTERWARDS
..ROUGH SWELLS FROM THE EAST-SOUTHEAST TO SOUTHEAST WILL CONTINUE
THE CHANCE FOR SMALL CRAFT ADVISORY MONDAY THROUGH WEDNESDAY...
ESPECIALLY FOR THE FAR OFFSHORE GULF OF MEXICO WATERS.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
55
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1048 AM CDT THU MAY 7 2015
.UPDATE...
DENSE FOG MOVED OUT OF THE NEARSHORE WATERS... PER WEBCAMS AND
VISIBLE SATELLITE IMAGERY. MID AND HIGH CLOUDS ARE STREAMING NORTH
ACROSS SOUTHERN WI THIS MORNING. WINDS ARE BEGINNING TO INCREASE AS
THE STRONG WINDS ALOFT MIX DOWN TO THE SURFACE. DEWPOINTS SHOULD
STAY MIXED AND IN THE 50S TODAY. TEMPERATURES ARE ON TRACK TO REACH
THE LOWER 80S TODAY... INCLUDING THE LAKESHORE COUNTIES. THERE WILL
BE PLENTY OF SUNSHINE... BUT IT WILL BE BREEZY WITH WIND GUSTS UP TO
30 MPH.
THERE IS STILL A CHANCE FOR SHOWERS TO TRACK INTO SOUTH CENTRAL WI
THIS AFTERNOON. THE 12Z NAM AND CANADIAN MODELS CAME IN WITH A
SIMILAR SOLUTION AS THEIR PREVIOUS RUNS THAT SHOW PRECIP TRACKING
ACROSS MUCH OF THE AREA PRIOR TO 00Z DUE TO A SHORTWAVE. THE HRRR
AND RAP MODELS HAVE A DRY FORECAST FOR SOUTH CENTRAL WI THIS
AFTERNOON AS OF RIGHT NOW... BUT THEY ARE NOT PICKING UP ON THE
SHOWERS DEVELOPING ALONG THE WI/IOWA BORDER AS OF 1030 AM. ANY
SHOWERS/TSTORMS MOVING INTO THE AREA WILL ENCOUNTER A WELL-MIXED...
DRY AND CAPPED ENVIRONMENT. THIS WILL LEAD TO DECAYING SHOWERS AS
THEY MOVE ENE.
&&
.AVIATION/18Z TAFS/...
A VFR PERIOD IS EXPECTED WITH ISOLD TO SCT THUNDER A BETTER
OVERNIGHT THREAT IN THE KMSN AREA...POSSIBLY REACHING ERN TAF SITES
LATE TNGT INTO FRI MRNG.
&&
.MARINE...
VEERING WINDS TO THE SOUTH TO SOUTHEAST WILL RESULT IN WIND GUSTS
APPROACHING SMALL CRAFT ADVY LEVELS THIS AFTERNOON. THEY ALSO LED
TO MARINE FOG SHIFTING WELL OFF SHORE AND NORTHWARD THIS MORNING.
THUS... THE MARINE DENSE FOG ADVISORY WAS CANCELLED.
&&
.PREV DISCUSSION... /ISSUED 354 AM CDT THU MAY 7 2015/
TODAY AND TONIGHT... FORECAST CONFIDENCE - MEDIUM.
FORECAST FOCUS ON MORNING FOG...WARM TEMPERATURES AND INCREASING
THUNDER THREAT. BOUNDARY LAYER WINDS HAVE STEADILY INCREASED
OVERNIGHT AND SHIFTED MORE TO THE SOUTH. RECENT DESCENT TAMDAR
SOUNDING INTO KMKE SHOWS SOUTH WINDS AT 24KTS ONLY 1800 FT OFF
GROUND. DENSE FOG HAS THINNED RAPIDLY IN LAST SEVERAL HOURS OVER
MOST OF EASTERN CWA. SOME LIGHTER FOG WL LIKELY CONTINUE INTO THE
EARLY MORNING DUE TO PERSISTENT LIGHT E WINDS AT THE SFC...BUT
EXPECT INSOLATION AND INCREASING SFC WINDS TO ERASE ALL FOG BY MID-
MORNING.
FOCUS OF CONVECTION TODAY REMAINS TO THE WEST IN THE PLAINS WHERE
WEAKENING MID-LEVEL TROF WILL BE NUDGED NORTHEAST BY UPPER LOW
SLIDING SOUTH ACROSS WESTERN CONUS. WILL KEEP MOST OF MORNING DRY
AND WITH AT LEAST PARTIAL SUNSHINE AND INCREASE SOUTH
WINDS...TEMPERATURES WILL RISE WELL INTO THE 70S...PEAKING IN THE
LOWER 80S IN THE AFTN. THE WARMER AIR WILL BE WELCOME CLOSER TO THE
LAKESHORE AS 925H TEMPS WARM TO AROUND 20C. LOCATIONS RIGHT ALONG
THE LAKESHORE WILL REMAIN A BIT COOLER...ESPECIALLY WIND POINT AND
NORTHERN OZAUKEE INTO SHEBOYGAN COUNTIES AS SFC WINDS WL REMAIN
SOUTH TO SOUTHEAST THIS AFTN.
WHILE MAIN SHORT WAVE TRAVELS NORTHEAST ACROSS NORTHERN
PLAINS...WEAKER UPSTREAM WAVE CURRENTLY OVER THE KS/MO AREA WILL
TRACK NORTHEAST ACROSS IOWA INTO CENTRAL WI TODAY INTO THIS EVENING.
PROTECTIVE RIDGE HAS MOVED OFF TO THE EAST...SO WITH DEEPER MOISTURE
IN THE AREA...THINKING SCATTERED -SHRA AND -TSTM WILL AFFECT WESTERN
CWA LATER THIS AFTN AND EVE. MUCAPE INCREASES TO 500 TO 1000 J/KG
IN THE WEST DURING THIS PERIOD...BUT STRONGEST CONVECTION TO REMAIN
TO THE WEST. 6KM SHEAR DOES INCREASE TO 25 TO 30 KTS SO NOT
IMPOSSIBLE ONE OR TWO STORMS TURN MORE RAMBUNCTIOUS NEAR NORTHWEST
CWA.
WEAKENING TROF AND FRONTOGENETICAL FORCING SLIDES ACROSS WI TONIGHT
AS COOL FRONT SLIDES INTO CENTRAL WI. WL CONTINUE LOWER POPS FOR
THE LATE NIGHT AND SPREAD CHANCE INTO ERN CWA.
FRIDAY AND FRIDAY NIGHT - CONFIDENCE...MEDIUM
500 MILLIBAR FLOW REMAINS SOUTHWEST WITH SURFACE/850 FRONTS
ENHANCING LOW LEVEL CONVERGENCE THIS PERIOD. IN ADDITION...250
MILLIBAR JET AND RIGHT REAR CONTRIBUTIONS SUGGEST FORCING WILL BE
ENHANCED WELL INTO THE EVENING HOURS SUPPORTING THE SLOWER FROPA
AND LINGERING SHRA/TSRA POTENTIAL PER ECMWF/NAM. GFS STILL PRETTY
QUICK ON EXITING PRECIP DURG THE EVE IN THE SE CORNER OF THE CWA.
NAM SOUNDINGS SHOW CAPE VALUES PUSHING 1000 J/KG.
SATURDAY - CONFIDENCE...MEDIUM
MID LEVEL FLOW REMAINS SOUTHWEST AND MODELS DO SHOW SOME VORT
ACTION IN THIS REGIME. SURFACE FRONT PROGGD TO BE SOUTH OF WI WITH
COOLER AND MORE STABLE NE SFC WIND. SFC RIDGING NUDGES SOUTH INTO
SRN WI. NEVERTHELESS SOME WEAK ISENTROPIC ASCENT COMBINED WITH
LINGERING UPPER DIVERGENCE AND EMBEDDED WAVES IN SOUTHWEST
FLOW...WILL KEEP SHRA CHCS GOING.
SUNDAY - CONFIDENCE...MEDIUM
UPPER LOW WILL BE LIFTING SLOWLY NORTHEASTWARD FROM THE CENTRAL
PLAINS. SUBSEQUENT SURFACE LOW DEVELOPMENT WILL TAKE SHAPE ACROSS
NEBRASKA. SURFACE BOUNDARY REMAINS DRAPED TO THE SOUTH OF WI. WITH
INCREASING SOUTHERLY 850 FLOW...THIS WILL ENHANCE ISENTROPIC LIFT
VICINITY 850 BAROCLINIC ZONE...SO POPS RISE TO THE LIKELY
CATEGORY. EASTERLY FLOW IS MAINTAINED THUS A COOL REGIME PERSISTS.
SUNDAY NIGHT AND MONDAY - CONFIDENCE...MEDIUM
UPPER LOW IN THE PLAINS PROGGD TO OPEN UP AND PROGRESS EAST WITH
PIECES OF NEGATIVELY TILTED SHORTWAVE ENERGY RIDING THROUGH DURING
THE PERIOD. SURFACE LOW OCCLUDES AND PLODS ACROSS SRN/CNTRL WI
VCNTY ON MONDAY. WILL HAVE HIGH POPS...WITH MODELS SHOWING HIGHEST
PRECIP POTENTIAL IN THE 6-18Z TIME FRAME. HIGHEST CWASP VALUES OF
60 TO 70 NOTED BEFORE 18Z WITH AXIS OF HIGHER PARAMETERS SHIFTING
EAST BY 00Z.
MONDAY NIGHT AND TUESDAY - CONFIDENCE...MEDIUM
AS SURFACE LOW PULLS AWAY...LOW LEVEL COLD ADVECTION WRAPS IN.
MID LEVEL FLOW REMAINS CYCLONIC WITH LOW LEVEL TROUGH AXIS HANGING
BACK AS WELL...SO WILL KEEP THE SUPERBLEND POPS FOR SHRA CHCS.
WEDNESDAY - CONFIDENCE...LOW
ECMWF SHOWS A QUICKER WAA RESPONSE AS NEXT LOW MOVES INTO THE PLAINS
WHILE THE GFS MODIFIES THE THERMAL TROUGH BUT KEEPS NORTHWEST 850
FLOW IN PLACE. ECMWF GENERATES QPF INTO NW WI WITH THE GFS DRY AND
NO SIGN OF AN APPROACHING LOW. WILL GO WITH THE DRY LOOK AT THIS
POINT AND EXPECT SOME MODIFICATION IN TEMPS FROM TUESDAY.
AVIATION/12Z TAFS/...INCREASING BOUNDARY LAYER WINDS JUST ABOVE SHALLOW
INVERSION OVERNIGHT HAS CAUSED THE DENSE FOG TO THIN. ONLY EXPECT PATCHY
LIGHT FOG INTO THE EARLY MORNING BEFORE COMPLETELY THINNING. THEN
A VFR PERIOD IS EXPECTED WITH ISOLD TO SCT THUNDER A BETTER OVERNIGHT
THREAT IN THE KMSN AREA...POSSIBLY REACHING ERN TAF SITES LATE TNGT
INTO FRI MRNG.
MARINE...BOUNDARY LAYER WINDS HAVE INCREASED OVERNIGHT TO THIN THE
DENSE FOG OVER MOST OF THE INLAND AREAS. HOWEVER LIGHT EAST TO SOUTHEAST
FLOW THIS MORNING AND WARM...HUMID AIR OVER THE COOL LAKE MI WATERS
SHOULD CONTINUE TO TRIGGER AREAS OF DENSE FOG OVER THE NEAR SHORE
WATERS. 11-3.9 MICRON IMAGERY SHOWS AREAS OF FOG LINGERING OVER
LAKE MI EARLY THIS MRNG. HENCE WILL CONTINUE DENSE FOG ADVY THRU
MOST OF THE MORNING.
WILL GET BETTER IDEA OF DENSE FOG EXTENT WITH NEW VSBL IMAGERY
AVAILABLE AFT 13Z.
VEERING WINDS TO THE SOUTH TO SOUTHEAST WILL RESULT IN WIND GUSTS
APPROACHING SMALL CRAFT ADVY LEVELS DURING THE AFTN. FOR NOW WL
COUNT ON SLIGHT ONSHORE COMPONENT OVER NEAR SHORE WATERS TO CONTINUE
SHALLOW LOW LEVEL INVERSION...PREVENTING STRONGER WINDS FROM MIXING
TO SURFACE. WL MENTION IN HWO.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...MBK
FRIDAY THROUGH WEDNESDAY...COLLAR
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
526 AM MDT THU MAY 7 2015
...A STRONG WINTER STORM SYSTEM WITH HEAVY SNOW FOR SOUTHEAST WYOMING
CONTINUES TO TAKE SHAPE FOR THIS WEEKEND...
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 526 AM MDT THU MAY 7 2015
WYDOT WEBCAMS CONTINUE TO INDICATE PATCHY FOG OVER THE INTERSTATE 80
SUMMIT AND ADJACENT FOOTHILLS EARLY THIS AM. PERSISTENT LLVL UPSLOPE
AND ABUNDANT BOUNDARY LAYER MOISTURE SHOULD REMAIN IN PLACE THROUGH
MID MORNING...SO EXPECT THIS TO CONTINUE FOR A FEW MORE HOURS. HAVE
NOT SEEN ANYTHING PARTICULARLY DENSE...SO DO NOT SEE ANY NEED FOR A
DENSE FOG ADVISORY AT THIS TIME. THE HRRR SHOWS LOCALLY REDUCED VSBY
TO AROUND ONE QUARTER OF A MILE THROUGH 15Z...THEN DISSIPATING. THIS
SEEMS TO MAKE SENSE WITH MOISTURE PROFILES ON BUFKIT SOUNDINGS. KCYS
RADAR LOOP SHOWS SHOWER ACTIVITY WINDING DOWN OVER FAR SOUTHEAST WY
INTO THE SOUTHERN NE PANHANDLE. THE NAM SHOWS WINDS SHIFTING TO THE
EAST/NORTHEAST AFTER 18Z AS A MID LEVEL DISTURBANCE MOVES OUT OF CO
AROUND THE SAME TIME. THIS FRAGMENTED WAVE WAS OBSERVED AT 12Z PER
RECENT WATER VAPOR IMAGERY. QPF SIGNALS INCREASE DRAMATICALLY DURING
THE AFTERNOON WITH THE RETURN OF EXCELLENT UPSLOPE...SO RAIN COULD
VERY WELL BECOME WIDESPREAD AGAIN LATER TODAY FROM THE HIGH COUNTRY
EASTWARD INTO CHEYENNE. PWAT VALUES REMAIN RESPECTABLE AROUND 0.5 TO
0.6 INCH...SO FELT COMFORTABLE BRINGING LIKELY POPS BACK INTO THE
PICTURE DURING THE LATE AFTN/EARLY EVE. THE NAM AND GFS BOTH SHOW A
RIBBON OF 500 J/KG SBCAPES ALONG THE I80 CORRIDOR IN OUR CWA...SO AT
LEAST A FEW LIGHTNING STRIKES ARE POSSIBLE. LIMITING FACTOR FOR ANY
AVAILABLE INSTABILITY WILL BE COOLER TEMPERATURES WITH UPSLOPE AND
RESULTING CLOUD COVER. THUNDERSTORMS COULD PRODUCE HAIL IN THIS TYPE
OF ENVIRONMENT IF THE MODELS VERIFY.
THINGS START TO GET INTERESTING ON FRIDAY AS A VIGOROUS LATE SEASON
WINTER STORM BEGINS TO TAKE SHAPE. WE ARE INDEED DEALING WITH A VERY
CHALLENGING FORECAST WITH RESPECT TO SNOW LEVELS AND RESULTING SNOW
AMOUNTS...AS WELL AS IMPACTS TO TRAVEL FOR MOTHERS DAY. GFS/NAM/ECM
ARE ALL IN EXCELLENT AGREEMENT WITH A VIGOROUS CLOSED LOW OVER THE
GREAT BASIN AT 12Z FRI. THIS FEATURE SLOWLY MEANDERS INTO THE FOUR
CORNERS REGION BY 06Z SAT WITH SURFACE CYCLOGENESIS RAMPING UP OVER
SOUTHEAST CO. ALL OF THE MODELS SHOW THIS SYSTEM LIFTING NORTHEAST
ON SAT NIGHT AND SUN WITH THE ASSOCIATED SUB-1000 MILLIBAR SURFACE
LOW SHIFTING INTO NORTHWEST KS. THIS TRACK ALLOWS MUCH COOLER AIR TO
SPILL INTO OUR HIGHER ELEVATION AREAS AS EARLY AS FRI NIGHT...WITH
H7 TEMPS FALLING TO -2C BY 12Z SAT. NAM WBZ HEIGHTS FALL TO AROUND
8000 FEET OR SO BY 09Z...AND FORECAST SOUNDINGS OVER THE SUMMIT ARE
FULLY SUPPORTIVE OF SNOW WHICH COULD BE HEAVY GIVEN A LAYER OF DEEP
SATURATION. A FEW PIECES OF ENERGY ROUNDING THE LOW WILL SUPPORT AN
INCREASE IN PCPN DURING THIS TIME...SO DO EXPECT THIS TO BE THE VERY
BEGINNING OF A POTENTIALLY SIGNIFICANT WINTER STORM EVENT. SLIGHTLY
NEGATIVE EPV VALUES SUGGEST ENOUGH INSTABILITY FOR A FEW CONVECTIVE
ELEMENTS AS WELL...FURTHER REINFORCING THE LIKELIHOOD OF SNOW.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 526 AM MDT THU MAY 7 2015
VERY CONCERNED THAT TRAVEL CONDITIONS MAY QUICKLY DETERIORATE BY SAT
MORNING...EVEN THOUGH THE MAIN SNOWFALL EVENT IS NOT EXPECTED UNTIL
LATER IN THE DAY ON SAT. THIS WOULD MAINLY BE OVER THE I80 SUMMIT...
BUT THIS AREA HAS BEEN A PROBLEM RECENTLY WITH VERY SIMILAR SYNOPTIC
SETUPS. WITH EARLY IMPACTS AND LIKELIHOOD OF MAJOR ACCUMULATIONS ON
SAT...WE DECIDED TO GO WITH A WINTER STORM WATCH FOR ALL OF OUR MTN
ZONES BEGINNING AT 06Z SAT. CONCERNING THE LATER EVOLUTION OF THIS
EVENT...NOTABLE COLD ADVECTION ALOFT APPEARS LIKELY ON SAT WITH H7
TEMPS FALLING TO BETWEEN -5 AND -10 DEG C ACROSS THE ENTIRE CWA BY
12Z SUN. THIS ULTIMATELY ALLOWS SNOW LEVELS TO FALL TO 5000 FEET OR
LOWER DURING THE COURSE OF THE EVENT. THE TRICKY PART WILL BE TIMING
WHEN THIS OCCURS FROM W TO E. ESPECIALLY CONCERNED ABOUT CHEYENNE AS
THE EUROPEAN SHOWS A DISTINCT COLD AIR DAMMING SIGNATURE DRAPED OVER
THE CO FRONT RANGE. THAT WAS OUR ACHILLES HEEL WITH THE LAST CLOSED
LOW WE DEALT WITH...AND IT KEPT WINDS NORTHERLY AT KCYS WITH COLDER
TEMPERATURES THAN MODELS PROGGED. THIS HAS BEEN THE ONLY MODEL TO
SHOW THIS SO FAR...BUT CAUTIOUSLY TRENDED LOWER ON TEMPS. THIS COULD
CAUSE SNOWFALL AMOUNTS TO BE SIGNIFICANTLY HIGHER AS THE HEAVIER
PCPN COULD VERY WELL BEGIN AS SNOW. WILL MAINTAIN A 6-10 INCH FCST
LOCALLY...BUT THIS MAY NEED TO BE REVISED. LATER SHIFTS WILL MOST
LIKELY NEED TO EXPAND THE WATCH EASTWARD INTO THE PLAINS. SHOULD
ALSO NOTE THAT GFS/SREF/NAM SOUNDINGS ALL SHOW A SUB-ZERO THERMAL
PROFILE AT LUSK ALL DAY ON SAT...SO COULD SEE SOME LOCALLY HIGHER
AMOUNTS IN THE HIGHER TERRAIN OUT THERE.
QPF SIGNALS FROM ALL MODELS ARE SCARY TO SAY THE LEAST. BUT ALAS...
THEY ARE BELIEVABLE WITH IMPRESSIVE MOISTURE (0.5 INCH PWATS FOR A
WINTER EVENT) COMBINED WITH EXCELLENT DYNAMIC SUPPORT BENEATH VERY
DIFLUENT FLOW AND A COUPLED UPPER JET. ALSO SEEING SOME INSTABILITY
IN THE MIX TOO WHICH WILL LIKELY LEAD TO MESOSCALE BANDING. NAM IS
STILL THE OUTLIER WITH THE HEAVIER PCPN DISPLACED WELL TO THE EAST
OF OUR CWA. GFS/ECMWF HAVE BEEN VERY CONSISTENT WITH WIDESPREAD 2-4
INCH LIQUID AMOUNTS...ESPECIALLY ALONG/EAST OF THE LARAMIE RANGE
WITH SIGNIFICANT UPSLOPE EXPECTED. THE NEW SREF IS TAGGING ALONG AS
WELL WITH HIGHER-END AMOUNTS. THAT SAID...CONFIDENCE IS VERY HIGH
THAT WE WILL SEE A SIGNIFICANT PRECIPITATION EVENT. WITH FORECAST
SOUNDINGS AS COLD AS THEY ARE...A FAIR AMOUNT OF THIS WILL PROBABLY
FALL AS SNOW. COULD SEE SEVERAL FEET IN THE MOUNTAINS. IT IS NOT
OUTSIDE OF THE REALM OF POSSIBILITY TO SEE A FOOT OR MORE FALL IN
CHEYENNE EITHER...BUT NEED TO SEE A FEW MORE MODEL RUNS TO BE SOLD
ON THAT SCENARIO. STAY TUNED AS THIS STORM APPEARS LIKELY TO GIVE US
QUITE A PUNCH. SNOW SHOULD FINALLY BEGIN TO DIMINISH BY SUN AFTN
AND/OR NIGHT AS THE LOW LIFTS INTO THE CENTRAL AND NORTHERN
PLAINS.
WITH THE LOW PRESSURE SYSTEM OPENING UP AND LIFTING OUT TO THE
NORTHEAST MONDAY...WE HAVE SOME LINGERING LIGHT SNOW SHOWERS IN
THE FORECAST FOR EARLY MONDAY MORNING...THEN WE SEE A CLEARING
AND WARMING TREND GOING THROUGH MIDWEEK. A RETURN OF DIURNAL
SHOWER/THUNDERSTORM CHANCES IS IN THE FORECAST BY LATE NEXT WEEK
AS WE SEE A NORTHWESTERLY FLOW ALOFT ON THE NORTHEAST SIDE OF A
4-CORNERS UPPER RIDGE. LOOKING JUST BEYOND THE 7 DAY FORECAST...
MODELS ARE SUGGESTING A MUCH WARMER AND DRIER WEEKEND FOR NEXT
WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 526 AM MDT THU MAY 7 2015
IFR FLIGHT CATEGORY CEILINGS CONTINUE FOR RAWLINS...LARAMIE AND
CHEYENNE THROUGH MID MORNING BEFORE LIFTING TO MVFR...WITH MVFR TO
VFR CEILINGS AND VISIBILITIES EXPECTED EAST ACROSS SCOTTSBLUFF...
SIDNEY...ALLIANCE AND CHADRON THROUGH MID MORNING. LATEST HRRR AND
HIGHER RESOLUTION MODEL GUIDANCE SUGGESTING NEXT ROUND OF SHOWERS
WILL COME THIS AFTERNOON AS CONVECTION FIRES OVER THE MOUNTAINS
WEST OF CHEYENNE AND LARAMIE...MOVING EAST INTO SOUTHEAST WYOMING
AND THE WESTERN NEBRASKA PANHANDLE THIS AFTERNOON. FOR NOW WE WILL
CARRY A MENTION OF THUNDER IN THE VICINITY FOR ALL AIRPORTS EXCEPT
CHADRON THIS AFTERNOON AND EVENING IN THE REGION OF MARGINAL
INSTABILITY.
&&
.FIRE WEATHER...
ISSUED AT 526 AM MDT THU MAY 7 2015
THE COOL AND WET WEATHER PATTERN WILL CONTINUE THROUGH THE
WEEKEND...WITH FAIRLY HIGH CHANCES FOR MEASURABLE RAINFALL OR
SNOW. A STRONG STORM SYSTEM WILL IMPACT THE DISTRICTS THIS WEEKEND
WITH POTENTIALLY WIDESPREAD AND HEAVY PRECIPITATION AMOUNTS...AS
WELL AS GUSTY NORTHERLY WINDS. THIS SYSTEM WILL BE COLD
ENOUGH...WITH SNOW LEVELS DROPPING TO AROUND 5000 FEET. MINIMUM
RELATIVE HUMIDITY VALUES WILL REMAIN WELL ABOVE CRITICAL
THRESHOLDS THROUGH THE FORECAST PERIOD. A TREND TOWARD WARMER AND
DRIER CONDITIONS WILL COMMENCE BY TUESDAY.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WATCH FROM LATE FRIDAY NIGHT THROUGH SUNDAY
AFTERNOON FOR WYZ103-112-114-116.
NE...NONE.
&&
$$
SHORT TERM...CLH/JG
LONG TERM...CLH
AVIATION...JG
FIRE WEATHER...JG
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
913 AM PDT Thu May 7 2015
.Synopsis...
A storm over NorCal will bring scattered showers or thunderstorms
through tonight with Sierra showers into Friday. Periods of breezy
north winds. Chance of showers or thunderstorms again early next
week mainly northern mountains.
&&
.Discussion (Today through Saturday)...
Have made a few updates this morning. Increased snow amounts in
the Sierra so that the Winter Weather Advisory now reflects snow
totals of 3-8 inches above 5000 ft around Hwy 50 southward. We
also increased the area of showers/thunderstorms for today as
this storm lingers over the region. Much of the shower activity
will be along the Interstate 80 corridor and southward today into
tonight. The high resolution HRRR model suggests that another wave
a precipitation could wrap around the Sierra towards the
Sacramento Metro region later tonight around 10 pm. Will look at
other models to see if we need to increase precipitation chances
for tonight. JBB
.Previous Discussion...Upper level closed low has dropped southward into
Northern California this morning. Disturbances pivoting around the
base of the low are generating showers over Norcal south of line
from about Chester to Clear Lake and north of about Sacramento.
The low is forecast to continue southward into Socal later today
and this evening. Stability progs show slightly unstable
conditions across much of the CWA so can not rule out a threat of
thunderstorms just about anywhere in the forecast area especially
this afternoon when daytime surface heating maxes out for the day.
Cool upper low will bring down daytime highs today to near normal
for this time of year. Surface high pressure pushing in behind the
upper low over the Pacific Northwest has created a fairly tight
surface gradient across the north state and this is producing
gusty north winds some areas. Current MFR to SAC gradient is 12mb.
Upper level support is only weak however so the strongest winds
are likely to be spotty and fairly short lived. Decreasing
gradients and winds are expected by this afternoon. Upper low is
progged to be over Socal by late this afternoon. Therefore focus
of heaviest precip expected to be over the Sierra south of about
Tahoe. Still looks to be enough snowfall at pass levels to justify
winter weather advisory currently in place from highway 50
southward. Upper low continues southeastward on Friday with rap
around moisture keeping a threat of showers over the Sierra but
allowing for warming temperatures most other locations. Upper low
moves eastward into the eastern Great Basin on Saturday bringing
clearing skies and still warmer temperatures but a disturbance
pivoting down the backside of the low could bring a stray shower
over the northern Sierra Saturday afternoon. Models show an upper
ridge over the west coast late Saturday and early Sunday so most
of the weekend should be under fair skies with daytime highs
pushing up to between 5 to 10 degrees above normal. A weak Pacific
low is forecast by mid range models to approach the coast late
Sunday bringing a threat of showers to the northwest corner of the
state by late Sunday afternoon or evening.
.Extended Discussion (Monday through Thursday)
Another upper low is forecast to dig south along the NW Cal coast
Monday. Models then differ significantly on how quickly to eject
the low by Wednesday. Potential for showers and thunderstorms
exist early next week, with Monday/Tuesday expected to be the most
active day. The GFS and GEM have more active weather with the low
over CA, while the EC tends to be drier and keeps the low offshore
of Oregon with only weak troughing over area. Cooling trend
expected with afternoon highs near to just below normal next week.
JClapp
&&
.Aviation...
Localized MVFR (bases 010 to 020) across area with showers and
t-storms today. Northerly sfc wind gusts to 30 kts today into
this evening. N-NE flight level 020 to 030 winds of 30-40 kts
late this aftn through evening as low moves south of area.
JClapp
&&
.STO Watches/Warnings/Advisories...
winter weather advisory until 5 am pdt friday west slope
northern sierra nevada.
&&
$$
AREA FORECAST DISCUSSION
NWS PUEBLO CO
310 PM MDT THU MAY 7 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 212 PM MDT THU MAY 7 2015
CURRENTLY...STEEP LOW LEVEL LAPSE RATES...FAIRLY COLD AIR ALOFT
AND SURFACE CAPES OVER 1000 J/KG HAVE COMBINED TO GENERATE VERY
EFFICIENT HAIL PRODUCING TSRA ACROSS EL PASO COUNTY...WITH 6-8 INCH
DEEP ACCUMULATIONS SLOWING TRAFFIC AND CAUSING DRAINAGE PROBLEMS
OVER THE NORTH SIDE OF COLORADO SPRINGS. TOUGH TO FIND MUCH UPPER
LEVEL FORCING...THOUGH THERE IS A HINT OF A WEAK SHORT WAVE LIFTING
NORTHEASTWARD THROUGH THE FOUR CORNERS IN THE LATEST WATER VAPOR
LOOP. ELSEWHERE ON THE PLAINS...CAPES RUNNING 1000-1500 J/KG....WITH
BEST INSTABILITY SOUTH OF THE ARKANSAS RIVER WHERE STRATUS CLEARED
FASTEST EARLIER THIS MORNING. FOR THE REMAINDER OF THE
AFTERNOON...SVR TSRA WATCH ISSUED FOR PLAINS ALONG AND EAST OF I-25
WITH MAIN THREAT BEING LARGE HAIL...THOUGH ISOLATED CELLS ACROSS LAS
ANIMAS/BACA COUNTIES HAVE SHOWN SOME SUPERCELLULAR CHARACTERISTICS
WITH A LEAST A LOW THREAT OF A TORNADO.
TONIGHT...TSRA MIGRATE EASTWARD THIS EVENING...WITH LATEST HRRR
KEEPING STRONGEST STORMS ALONG THE PALMER DIVIDE AND ACROSS LAS
ANIMAS/BACA COUNTIES THROUGH THE EVENING BEFORE A LOOSELY ORGANIZED
LINE FORMS NEAR THE KS BORDER LATER IN THE EVENING. HRRR ALSO HINTS
AT A NEW ROUND OF CONVECTION ALONG THE I-25 CORRIDOR IN PUEBLO/EL
PASO COUNTIES 05Z-06Z AS OUTFLOW ENHANCED UPSLOPE FLOW PUSHES BACK
WESTWARD. OVERALL...WILL KEEP POPS IN PLACE MOST LOCATIONS THROUGH
THE NIGHT...HIGHEST CHANCES EL PASO/TELLER COUNTIES.
THURSDAY...STILL A FEW LINGERING -SHRA DURING THE MORNING WITH LOW
LEVEL MOISTURE/UPSLOPE AND WEAK WARM ADVECTION LIFT DEVELOPING OVER
THE OLD FRONTAL BOUNDARY. BY AFTERNOON...EXPECT WARM FRONT TO LIE
ALONG THE NM BORDER AROUND MIDDAY BEFORE LIFTING NORTHWARD TOWARD
THE ARK RIVER BY EVENING. ALONG AND NORTH OF THE BOUNDARY...EASTERLY
BL FLOW COMBINED WITH FAIRLY DEEP INSTABILITY WILL LEAD TO ANOTHER
ROUND OF STRONG TO SEVERE THUNDERSTORMS AS CAPES RANGE FROM 1-2K
J/KG AND 0-6KM SHEAR APPROACHES 50 KTS. ELSEWHERE OVER THE MOUNTAINS
AND HIGH VALLEYS...LITTLE CHANGE IN THE PATTERN AS SCT AFTERNOON
TSRA WILL DEVELOP ONCE AGAIN...WITH HIGHEST POPS GENERALLY OVER THE
NORTHERN HALF OF THE AREA. MAX TEMPS LITTLE CHANGED WITH
CLOUDS/MOISTURE/PRECIP PERSISTING.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 212 PM MDT THU MAY 7 2015
THERE IS A HIGH DEGREE OF ENSEMBLE SPREAD THROUGH THE EXTENDED
PERIOD WITH ACTIVE WEATHER LOOKING TO CONTINUE FOR THE NEXT
SEVERAL DAYS. CONFIDENCE IN THE FORECAST IS ON THE HIGHER SIDE
THROUGH THE WEEKEND...WITH LESS CONFIDENCE EARLY TO MIDDLE NEXT
WEEK.
FRIDAY NIGHT THROUGH SUNDAY NIGHT...A STRONG UPPER LEVEL LOW
PRESSURE SYSTEM IS FORECAST TO MOVE OUT OF THE DESERT
SOUTHWEST...NORTHEAST ACROSS SOUTHERN COLORADO INTO THE NORTHERN
PLAINS. SEVERAL ROUNDS OF WEATHER ARE EXPECTED WITH THIS STORM
SYSTEM AND PREPARATIONS SHOULD BE MADE FOR MOUNTAIN
SNOWFALL...SEVERE WEATHER ON THE PLAINS AND FLOODING POTENTIAL IN
SATURATED AREAS.
A SHORTWAVE TROUGH WILL BE EJECTING AROUND THE LOW ACROSS
COLORADO FRIDAY NIGHT. EXPECT SHOWER AND THUNDERSTORM ACTIVITY TO
BE ONGOING ACROSS THE REGION. SHEAR AND INSTABILITY WILL BE
SUFFICIENT FOR A FEW STRONG TO SEVERE THUNDERSTORMS FRIDAY
EVENING...ESPECIALLY EAST OF A LA JUNTA TO KIM LINE. STRONG WINDS
AND LARGE HAIL ARE THE PRIMARY THREATS...AND AN ISOLATED TORNADO
IS POSSIBLE. THESE STORMS WILL SHIFT EAST INTO WESTERN KANSAS
THROUGH THE LATE EVENING HOURS. ELSEWHERE...SHOWERS AND
THUNDERSTORMS WILL CONTINUE ACROSS THE MOUNTAINS AND ADJACENT
PLAINS. LOCALLY HEAVY RAINFALL IS POSSIBLE AND SMALL HAIL FRIDAY
EVENING. IF A STRONGER STORM CAN IMPACT TELLER AND EL PASO
COUNTIES...FLASH FLOODING WILL BE POSSIBLE. THIS ACTIVITY SHOULD
CONTINUE THROUGH FRIDAY NIGHT.
THE UPPER LEVEL LOW IS FORECAST TO MOVE NORTHEAST ACROSS SOUTHERN
INTO EASTERN COLORADO ON SATURDAY. SEVERAL CONCERNS AS THE UPPER
SYSTEM EJECTS ACROSS THE AREA...THE POTENTIAL FOR SEVERE WEATHER
ALONG THE KANSAS BORDER...HEAVY RAINFALL WRAPPING AROUND THE
SYSTEM OVER THE PALMER DIVIDE AND INTO THE RAMPART RANGE AND SNOW
LEVELS. ALL OF THESE WEATHER CONCERNS WILL DEPEND ON THE EXACT
STORM PATH. THE NAM AND ECMWF HAVE A MORE FAVORABLE SOUTHERN
SOLUTION...WHILE THE GFS IS SLIGHTLY NORTH AND WOULD LIMIT THE
HEAVY RAINFALL THREAT IN PARTICULAR. AS FOR THE SEVERE WEATHER
THREAT...MODELS ARE IN GOOD AGREEMENT WITH A DRYLINE DEVELOPING
OVER THE EASTERN PLAINS AND TRACKING THROUGH THE AFTERNOON.
CONVECTION IS FORECAST TO DEVELOP ALONG THE DRYLINE DURING THE
AFTERNOON HOURS...AND STORMS THAT DO DEVELOP WILL LIKELY BECOME
SEVERE. THE MAIN QUESTION IS HOW FAR EAST OR WEST THE STORMS
DEVELOP. HAVE A FEELING THE SEVERE WEATHER THREAT WILL BE LIMITED
TO ALONG THE KANSAS BORDER. ELSEWHERE...FLOW BEHIND THE SURFACE
LOW WILL PROVIDE STRONG LOW LEVEL UPSLOPE FLOW OVER THE PALMER
DIVIDE INTO THE RAMPART RANGE. THIS UPSLOPE FLOW COMBINED WITH
ABUNDANT MOISTURE WILL PROVIDE A FOCUS FOR HEAVY RAINFALL ALONG
THE LEE SLOPES OF THE RAMPART RANGE AND PALMER DIVIDE. THESE AREAS
HAVE SEEN HEAVY RAINFALL LATELY AND ARE SATURATED...AND FLOODING
WILL BE POSSIBLE...ESPECIALLY WITH THE ECMWF AND NAM STORM TRACK.
SNOW LEVELS WILL LIKELY BE HIGH THROUGH THE DAY ON SATURDAY WITH
SEVERAL INCHES EXPECTED ABOVE 10 KFT.
THE UPPER LEVEL LOW WILL PULL OFF INTO THE CENTRAL PLAINS SATURDAY
NIGHT INTO SUNDAY. WRAP AROUND FLOW AND SOME MODELS ARE PRODUCING
A TROWAL FEATURE OVER NORTHERN COLORADO KEEPING DECENT
PRECIPITATION ACROSS MUCH OF THE REGION. GFS HAS THIS FEATURE
NORTH...HOWEVER THE ECMWF AND NAM ARE SOUTH AND HAVE THIS FEATURE
IMPACTING THE AREA THROUGH SUNDAY MORNING. COLD AIR WILL BE
FILTERING INTO THE REGION WHICH WILL LIKELY DROP SNOW LEVELS DOWN
TO AROUND 7 KFT SUNDAY MORNING. THIS COULD LEAD TO SNOW ON THE
PALMER DIVIDE AND AN INCH OR TWO OF ACCUMULATION GRASSY SURFACE.
EXPECT MOST AREAS TO SEE CONTINUED SHOWER ACTIVITY IN THE COLD
WRAP AROUND FLOW THROUGHOUT THE DAY ON SUNDAY.
MONDAY THROUGH THURSDAY...THE UPPER SYSTEM WILL BE SHIFTING OFF
TO THE NORTHEAST WITH THE NEXT SYSTEM TAKING SHAPE BY THE MIDDLE
OF THE WEEK. EXPECT CONTINUED SHOWER AND THUNDERSTORM ACTIVITY
EACH AFTERNOON AND EVENING ACROSS THE MOUNTAINS...MOVING OUT IN
THE PLAINS. THE NEXT SYSTEM WILL LIKELY IMPACT THE AREA WEDNESDAY
INTO THURSDAY WITH ANOTHER ROUND OF WIDESPREAD SHOWER AND
THUNDERSTORM ACTIVITY BY THURSDAY. MOZLEY
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 212 PM MDT THU MAY 7 2015
ISOLD TO SCT TSRA WILL CONTINUE ALL AREAS INTO THE
EVENING...BEST CHANCES AT TAF SITES WILL BE AT KCOS AND KPUB...WITH
STORMS POTENTIALLY PRODUCING LARGE VOLUMES OF HAIL. TS THREAT
GRADUALLY ENDS THIS EVENING...THOUGH SOME -SHRA MAY LINGER PAST 06Z
OVER THE EASTERN MOUNTAINS AND ALONG THE I-25 CORRIDOR. AS LOW LEVEL
MOISTURE SLOSHES BACK WESTWARD OVERNIGHT...EXPECT STRATUS TO
REDEVELOP OVER THE PLAINS WITH IFR CIGS FOR SEVERAL HOURS AROUND
SUNRISE AT KCOS...WHILE MVFR CIGS DEVELOP NEAR KPUB. EXPECT YET MORE
SCT AFTERNOON TSRA ON FRI...WITH A THREAT FOR SEVERE TSRA AT KCOS
AND KPUB AFTER 19Z.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...PETERSEN
LONG TERM...MOZLEY
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS NEW YORK NY
634 PM EDT THU MAY 7 2015
.SYNOPSIS...
HIGH PRESSURE JUST OFFSHORE TO OUR EAST WILL HEAD FARTHER OUT
INTO THE WESTERN ATLANTIC THROUGH THE WEEKEND. LOW PRESSURE WILL
REMAIN NEARLY STATIONARY NEAR THE CAROLINAS THIS
WEEKEND...BRINGING AN INCREASE IN HUMIDITY THROUGH MONDAY. A COLD
FRONT WILL APPROACH ON TUESDAY...AND PASS OFFSHORE ON WEDNESDAY.
HIGH PRESSURE BUILDS ACROSS THE AREA ON WEDNESDAY AND THURSDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
HIGH PRESSURE WILL BE CENTERED JUST OFF TO OUR EAST. LATEST
GUIDANCE INCLUDING HRRR AND NARRE INDICATE STRATUS CURRENTLY
OBSERVED OFF THE NJ COAST EXPANDING NORTHWARD AND SPREADING
ACROSS THE LI COAST. DEW POINTS AT THE BUOYS OBSERVED CLOSE TO
WATER TEMPS...BUT STILL MUCH LOWER OVER LAND. WILL NEED TO KEEP
AN EYE ON THIS POSSIBLE EXPANSION NORTHWARD. OTHERWISE...THE
COMBINATION OF CLEAR SKIES AND LIGHT WINDS WITH SOME INCREASE OF
SFC MOISTURE LEVELS SHOULD LEAD TO AT LEAST PATCHY RADIATION FOG
LATE TONIGHT.
TEMPS TONIGHT WILL BE AROUND 5-10 DEGREES WARMER THAN LAST NIGHT IN
MOST LOCATIONS.
&&
.SHORT TERM /FRIDAY NIGHT/...
SUNNY ON FRIDAY WITH AN UPPER RIDGE AXIS SHIFTING IN FROM THE WEST.
SEA BREEZES LIKELY DEVELOP AGAIN AS WINDS THROUGH THE MIXED LAYER
WILL BE LIGHT DURING THE MORNING. MIXING PROFILE LOOKS SIMILAR TO
EARLIER TODAY...BUT TOP OF THE MIXED LAYER SHOULD BE A LITTLE
WARMER. HAVE GONE ABOVE GUIDANCE FOR HIGH TEMPS FOR SEVERAL AREAS
BASED ON THIS. HIGHS IN THE 80S FOR SEVERAL INLAND LOCATIONS AS
WELL AS FOR PARTS OF THE CITY AND NORTHERN PARTS OF LONG ISLAND.
70S JUST ABOUT EVERYWHERE ELSE.
BETTER AGREEMENT AMONG THE MODELS FOR STRATUS AND AREAS OF FOG
MOVING IN FOR FRIDAY NIGHT AS HIGHER DEWPOINTS ADVECT OVER THE
COLDER SEA SURFACE TEMPERATURES. LIFT LOOKS WEAK...SO WILL GO WITH
A DRY FORECAST...BUT PATCHY DRIZZLE COULD OCCUR.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AN UPPER LEVEL RIDGE PERSISTS ACROSS THE EASTERN SEABOARD THIS
WEEKEND WHILE A SURFACE LOW SPINS OFF THE CAROLINA COAST. A SOUTH
TO SOUTHEAST FLOW WILL CONTINUE TO PUSH WARM MOIST AIR ACROSS THE
AREA OVER THE WEEKEND. THIS SHOULD ALLOW FOR SOME EXTENSIVE FOG
AND DRIZZLE. THE FOG WILL BURN OFF EACH DAY ACROSS THE INTERIOR
SECTIONS FIRST..WITH PLACES ALONG THE COAST HOLDING ON TO THE FOG
LONGER AND POSSIBLY NOT BURNING THRU THE FOG AT ALL.
ON MONDAY...WITH SOUTH WINDS INCREASING AND THE WARM MOIST AIR
STILL IN PLACE...WILL CONTINUE TO MENTION A CHANCE OF SHOWERS AND
THUNDERSTORMS. A COLD FRONT IS THEN FORECAST TO CROSS THE AREA ON
TUESDAY WITH MOISTURE FROM THE LOW PRESSURE SYSTEM NEAR THE
CAROLINA COAST INCREASING. THIS MAY RESULT IN THE DEVELOPMENT OF
SCATTERED SHOWERS AND THUNDERSTORMS THAT MAY PRODUCE SOME NEEDED
RAINS ON TUESDAY INTO EARLY WEDNESDAY. DRY AIR MOVES INTO THE AREA
WEDNESDAY AND THURSDAY AS HIGH PRESSURE BUILDS IN FROM THE WEST.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
VFR - SKY CLEAR. HIGH PRESSURE OVER THE REGION.
SOME GROUND FOG IS EXPECTED AROUND SUNRISE...THOUGH NOT
ANTICIPATING MUCH IN THE WAY OF IMPACT EVEN IN THE MORE FOG PRONE
SATELLITE TERMINALS.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: HIGH CONFIDENCE IN WIND DIRECTION 170-190
MAGNETIC FOR AFTN DEPARTURE BANK. GUSTS NOT EXPECTED.
KLGA FCSTER COMMENTS: HIGH CONFIDENCE IN WIND FCST.
KEWR FCSTER COMMENTS: HIGH CONFIDENCE THAT WIND DIRECTION STAYS
SOUTH OF 130 MAGNETIC...ESPECIALLY AS THE AFTN PROGRESSES.
KTEB FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KHPN FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KISP FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
.OUTLOOK FOR 18Z FRI THROUGH TUE...
.FRI AFTN...VFR.
.FRI NGT-TUE...HIGH POTENTIAL FOR LATE NIGHT AND EARLY MORNING
IFR/LIFR CONDS IN FOG AND STRATUS. OTHERWISE VFR.
&&
.MARINE...
NEED TO KEEP ON EYE ON FOG OVERNIGHT AND INTO FRIDAY. WINDS AND
SEAS REMAIN BLW SCA LVLS INTO MON WITH A WEAK SLY FLOW. AS THE
FLOW INCREASES IN ADVANCE OF A COLD FRONT...SEAS INCREASE TO ABOVE
SCA LEVELS TUESDAY AND REMAINING THROUGH THE MIDDLE OF THE WEEK.
SEAS FALL BACK TO BELOW SCA LEVELS ON THURSDAY AS HIGH PRESSURE
BUILDS ACROSS THE AREA WATERS.
&&
.HYDROLOGY...
NO RAIN IS EXPECTED THROUGH THE WEEKEND. SOME ORGANIZED PCPN IS
POSSIBLE TUESDAY INTO WEDNESDAY IN ASSOCIATION WITH A COLD
FRONTAL PASSAGE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JC/FIG
NEAR TERM...JC/PW
SHORT TERM...JC
LONG TERM...FIG
AVIATION...TONGUE
MARINE...JC/FIG/PW
HYDROLOGY...JC/FIG
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
621 PM EDT THU MAY 7 2015
.SYNOPSIS...
HIGH PRESSURE WILL BE IN PLACE ACROSS THE REGION TONIGHT
WITH A SECONDARY AREA OF HIGH PRESSURE BUILDING ACROSS THE MID
ATLANTIC STATES ON FRIDAY. THIS FEATURE WILL BE IN PLACE THROUGH THE
WEEKEND WITH AN AREA OF LOW PRESSURE OFF THE CAROLINA COASTLINE. FOR
THE EARLY PART OF NEXT WEEK, A COLD FRONT WITH AN ASSOCIATED AREA
OF LOW PRESSURE WILL MOVE ACROSS THE CENTRAL AND EASTERN UNITED
STATES AS THE LOW OFF THE CAROLINA COASTLINE WEAKENS. HIGH
PRESSURE WILL BUILD IN BEHIND THE COLD FRONT FOR THE MIDDLE PART
OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
WITH AN INTERMEDIATE UPDATE WE WERE MORE AGGRESSIVE WITH THE
ADVECTION OF FOG ONTO LAND AREAS FOR TONIGHT. LATEST HRRR
AND NARRE EMPHASIZING DELMARVA AND SERN NJ AS MOST FOG PRONE.
THERE IS ALREADY SOME PATCHY DENSE FOG FROM ACY SOUTHWARD. THERE
ARE DIFFERENCES IN THE NARRE VS THE HRRR AS TO THE EXTENT OF THE
DENSE FOG. THE FORMER IS RESTRICTED MORE TO JUST COASTAL SUSSEX
WHILE THE LATTER WRAPS UP THE DELAWARE NEARLY TO PHILLY.
CONFIDENCE ABOUT THE FOG IS NOT HIGH, BUT WE WILL FOLLOW TRENDS
AND SEE HOW QUICK THE SUNSET ADVECTION IS AND LIKELY MAKE A
DECISION WITH THE NEXT PLANNED UPDATE.
REST OF THE CWA REMAINS QUIET AND JUST SOME CURRENT TEMP AND DEW
POINTS ADJUSTMENTS WERE MADE THERE.
FAIR WEATHER TO CONTINUE OVERNIGHT WITH HIGH PRESSURE MOVING
OFFSHORE. PATCHY FOG OVERNIGHT MOST AREAS...PERHAPS NOT AS MUCH
FAR NORTH. MORE WIDESPREAD AREAS OF FOG ALONG THE SRN NJ/DELMARVA.
LOWS OVERNIGHT WILL DROP INTO THE MID/UPPER 50S MOST AREAS.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
FAIR WEATHER WILL CONTINUE FRIDAY. THERE WILL STILL BE SOME FOG
AROUND EARLY...BUT THE SUN WILL QUICKLY BURN THINGS OFF BY AROUND 8
AM OR SO. ITS POSSIBLE THAT SOME FOG MAY LINGER ACROSS THE
COAST...LIKE TODAY. HIGH TEMPS FRI WILL RISE INT THE UPPER 70S/LOW
80S MOST AREAS...COOLER NEAR THE SHORE. WINDS SHOULD MOSTLY S OR SW
AT 5 TO 10 MPH DURING THE DAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
GOOD AGREEMENT WITH THE VARIOUS ENSEMBLE AND OPERATIONAL MODELS
WITH THE GENERAL OVERALL PATTERN IN ALL PERIODS. THE MAIN
DISCREPANCY IS THE ECMWF AND THE ECMWF NUMERICAL GUIDANCE LOOK TO
COOL IN THE THREE TO FIVE DAY, WHILE THE GFS IS PERHAPS A TAD TO
WARM. ANY TROPICAL DEVELOPMENT OF THE LOW PRESSURE SYSTEM OFF THE
CAROLINAS MAY LEAD TO HIGHER RAIN CHANCES EARLY NEXT WEEK WITH ANY
OTHER IMPACTS TO DAILY WEATHER VERY LIMITED. DETAILS BELOW...
THIS WEEKEND: WITH HIGH PRESSURE LOCATED TO OUR NORTHEAST AND A LOW
PRESSURE OFF THE CAROLINA COAST A SOUTHEASTERLY FLOW WILL BE IN
PLACE. MOISTURE WILL BE ON THE INCREASE EACH DAY ALONG WITH RISING
925 MB TEMPERATURES AS A WARMER AIRMASS IS ADVECTED INTO THE REGION.
MANY LOCATIONS ARE LIKELY TO GET INTO THE LOW/MID 80`S ON AVERAGE
AFTER STARTING OUT IN THE UPPER 50`S/LOW 60`S. THE SOUTHEAST FLOW IS
LIKELY TO KEEP TEMPERATURES ALONG THE COAST COOLER. WITH THE LIGHT
SOUTHEASTERLY FLOW SOME MORNING FOG EACH DAY COULD OCCUR. ALSO THE
INCREASED INSTABILITY AND HUMIDITY MAY LEAD TO AN ISOLATED SHOWER OR
STORM. NO TRIGGER IN THIS PERIOD FOR ANYTHING MORE THAN ISOLATED TO
PERHAPS SCATTERED SHOWERS AND STORMS, GOING SLIGHT CHANCE ATTM.
MONDAY AND TUESDAY: A COLD FRONT WILL MOVE INTO THE REGION BY
TUESDAY ALONG WITH MOISTURE INCREASING FROM A DECAYING LOW PRESSURE
SYSTEM NEAR OR NORTH OF THE CAROLINAS. THESE TWO FEATURES WILL
RESULT IN THE DEVELOPMENT OF SCATTERED SHOWERS AND THUNDERSTORMS
THAT MAY PRODUCE SOME NEEDED RAINS. ENOUGH SEPARATION WITH THESE
FEATURES WILL LIMIT THE WIDESPREAD HEAVY RAIN THREAT BUT SOME
LOCALIZED DOWNPOURS ARE POSSIBLE. LOW LEVEL MOISTURE AND LIGHT
WINDS MAY RESULT IN ADDITIONAL PERIODS OF PATCHY FOG. RISING 925 MB
TEMPERATURES TO AROUND 20C SHOULD ALLOW INLAND AREAS TO RUN WELL
ABOVE CURRENT NUMERICAL GUIDANCE AND MODELED TWO METER TEMPERATURES
IN THE MID 80`S WITH OVERNIGHT LOWS EACH MORNING IN THE LOW TO MID
60`S. IN TERMS OF ANY SEVERE THREAT WITH THE FRONT, THIS LOOKS
LIMITED AS THE BEST DYNAMICS WILL BE NORTHWEST OF THE MORE
FAVORABLE INSTABILITY ATTM. AREAS THAT DO NOT SEE THE SCATTERED
STORMS WILL SLIP CLOSER TO DROUGHT CONDITIONS AS SHORT TERM DEFICITS
WITH RAINFALL CONTINUE TO GROW.
WEDNESDAY AND THURSDAY: AFTER THE COLD FRONTAL PASSAGE, HIGH
PRESSURE WILL BUILD INTO THE REGION WITH A DRIER AND COOLER AIRMASS.
GOING WITH A LARGER TEMPERATURE SPREAD THAN THE MODELED TWO METER
VALUES. CONSIDERABLE SUNSHINE MAY STILL ALLOW FOR HIGHS INTO THE
70`S AFTER CHILLIER STARTS IN THE 40`S/50`S. THE MAIN CONCERN MAY
END UP BEING FAVORABLE CONDITIONS FOR FIRE SPREAD. RH VALUES AROUND
35% EACH AFTERNOON COUPLED WITH STRONG WEST-NORTHWEST WINDS ARE
POSSIBLE.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE,
KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS.
BASICALLY A FAIR WEATHER PATTERN ACROSS THE REGION TONIGHT AND
FRIDAY. HIGH PRESSURE WILL MOVE OFFSHORE TONIGHT AND LITTLE
CLOUDINESS OR WIND IS EXPECTED. THERE IS THE POSSIBILITY FOR FOG
OVERNIGHT WITH THE LOW LEVEL MOISTURE SLOWLY INCREASING ACROSS THE
AREA. WE HAVE KEPT THE FOG FROM THE EARLIER TAFS...AND ADDED A FEW
AREAS SINCE CONDITIONS LOOK RATHER FAVORABLE. THE FOG WILL LIKELY
BURN OFF IN THE 12Z-13Z FRAME FRI WITH VFR AFTER THAT.
OUTLOOK...
FRIDAY NIGHT THROUGH SUNDAY: VFR WITH SOUTH-SOUTHEAST WINDS UNDER 10
KNOTS. SOME MORNING PATCHY LOW FOG POSSIBLE, BEST CHANCES AT RDG,
ACY AND MIV.
MONDAY AND TUESDAY: VFR THROUGHOUT MOST OF THIS PERIOD. SOME
SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE IN THE AFTERNOON AND
EARLY EVENING EACH DAY LEADING TO MVFR OR LOWER CONDITIONS. SOUTHEAST
WIND GUSTS UNDER 15 KNOTS ON MONDAY AND THEN SOUTHWEST WIND GUSTS
AROUND OR UNDER 20 KNOTS ON TUESDAY. PATCHY FOG POSSIBLE MONDAY
MORNING BEFORE 12Z.
&&
.MARINE...
AFTER COORDINATING WITH THE DAY SHIFT, WE HAVE DECIDED TO ISSUE A
DENSE FOG ADVISORY FOR OUR AREA WATERS THROUGH FRIDAY MORNING.
SOME OF THE TRAFFIC CAMS ALONG THE IMMEDIATE COAST LOOKED VERY
FOGGY. LATEST SREF/NARRE AND HRRR GUIDANCE ARE INDICATING THAT THE
FOG SHOULD CONTINUE AND SPREAD THROUGH THE NIGHT. NOT A CONFIDENT
FORECAST OFF OF MONMOUTH AND IN UPPER DELAWARE BAY AND TIMING
MIGHT HAVE TO BE EXTENDED ON FRIDAY AS FLOW REMAINS WEAK AND DEW
POINTS ABOVE WATER TEMPS.
SUB SCA CONDITIONS WITH FAIR WEATHER TONIGHT AND FRIDAY. THERE IS
SOME FOG ACROSS SE NJ/DEL COASTAL AREAS AND INTO SRN DEL BAY AND
EVEN INTO THE AFTERNOON...IT CONTINUES . IT WILL PROBABLY REMAIN INTO
THE EVENING AND PERHAPS BECOME A BIT MORE CONCENTRATED OVERNIGHT. VERY
LIGHT ONSHORE OR UP THE BAY FLOW INTO EARLY TONIGHT THEN
LIGHT/VARIABLE OVERNIGHT.
OUTLOOK...
SEAS AND WINDS ARE LIKELY TO REMAIN BELOW SCA CRITERIA THROUGH MONDAY
WITH SEAS NEAR FIVE FEET MONDAY NIGHT AND TUESDAY AS A COLD FRONT
APPROACHES. WINDS WILL BE MAINLY FROM THE SOUTH AND SOUTHEAST THROUGH
MONDAY THEN FROM THE SOUTHWEST UNDER 15 KNOTS WITH GUSTS UNDER 20
KNOTS, HIGHEST ON TUESDAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 9 AM EDT FRIDAY FOR ANZ431-451>455.
DENSE FOG ADVISORY UNTIL 9 AM EDT FRIDAY FOR ANZ430-450.
&&
$$
SYNOPSIS...GAINES
NEAR TERM...O`HARA
SHORT TERM...GIGI/O`HARA
LONG TERM...GAINES
AVIATION...GAINES/O`HARA
MARINE...GAINES/GIGI/O`HARA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
428 PM EDT THU MAY 7 2015
.SYNOPSIS...
HIGH PRESSURE WILL BE IN PLACE ACROSS THE REGION TONIGHT
WITH A SECONDARY AREA OF HIGH PRESSURE BUILDING ACROSS THE MID
ATLANTIC STATES ON FRIDAY. THIS FEATURE WILL BE IN PLACE THROUGH THE
WEEKEND WITH AN AREA OF LOW PRESSURE OFF THE CAROLINA COASTLINE. FOR
THE EARLY PART OF NEXT WEEK, A COLD FRONT WITH AN ASSOCIATED AREA
OF LOW PRESSURE WILL MOVE ACROSS THE CENTRAL AND EASTERN UNITED
STATES AS THE LOW OFF THE CAROLINA COASTLINE WEAKENS. HIGH
PRESSURE WILL BUILD IN BEHIND THE COLD FRONT FOR THE MIDDLE PART
OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
NICE WEATHER ACROSS MUCH OF THE AREA TODAY. THERE CONTINUES TO BE
AREAS OF FOG ALONG THE SRN HALF OF NJ`S SHORE AREAS AND ACROSS SRN
DEL BAY AND DE COASTAL AREAS. BRIGHT SUNSHINE AND LIGHT WINDS
ELSEWHERE. TEMPERATURES IN THE UPPER 70S/LOW 80S INLAND AND LOW/MID
70S CLOSER TO THE SHORE...BUT IN THE 60S NEAR THE IMMEDIATE COAST.
FAIR WEATHER TO CONTINUE OVERNIGHT WITH HIGH PRESSURE MOVING
OFFSHORE. PATCHY FOG OVERNIGHT MOST AREAS...PERHAPS NOT AS MUCH FAR
NORTH. MORE WIDESPREAD AREAS OF FOG ALONG THE SRN NJ/DELMARVA. LOWS
OVERNIGHT WILL DROP INTO THE MID/UPPER 50S MOST AREAS.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
FAIR WEATHER WILL CONTINUE FRIDAY. THERE WILL STILL BE SOME FOG
AROUND EARLY...BUT THE SUN WILL QUICKLY BURN THINGS OFF BY AROUND 8
AM OR SO. ITS POSSIBLE THAT SOME FOG MAY LINGER ACROSS THE
COAST...LIKE TODAY. HIGH TEMPS FRI WILL RISE INT THE UPPER 70S/LOW
80S MOST AREAS...COOLER NEAR THE SHORE. WINDS SHOULD MOSTLY S OR SW
AT 5 TO 10 MPH DURING THE DAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
GOOD AGREEMENT WITH THE VARIOUS ENSEMBLE AND OPERATIONAL MODELS
WITH THE GENERAL OVERALL PATTERN IN ALL PERIODS. THE MAIN
DISCREPANCY IS THE ECMWF AND THE ECMWF NUMERICAL GUIDANCE LOOK TO
COOL IN THE THREE TO FIVE DAY, WHILE THE GFS IS PERHAPS A TAD TO
WARM. ANY TROPICAL DEVELOPMENT OF THE LOW PRESSURE SYSTEM OFF THE
CAROLINAS MAY LEAD TO HIGHER RAIN CHANCES EARLY NEXT WEEK WITH ANY
OTHER IMPACTS TO DAILY WEATHER VERY LIMITED. DETAILS BELOW...
THIS WEEKEND: WITH HIGH PRESSURE LOCATED TO OUR NORTHEAST AND A LOW
PRESSURE OFF THE CAROLINA COAST A SOUTHEASTERLY FLOW WILL BE IN
PLACE. MOISTURE WILL BE ON THE INCREASE EACH DAY ALONG WITH RISING
925 MB TEMPERATURES AS A WARMER AIRMASS IS ADVECTED INTO THE REGION.
MANY LOCATIONS ARE LIKELY TO GET INTO THE LOW/MID 80`S ON AVERAGE
AFTER STARTING OUT IN THE UPPER 50`S/LOW 60`S. THE SOUTHEAST FLOW IS
LIKELY TO KEEP TEMPERATURES ALONG THE COAST COOLER. WITH THE LIGHT
SOUTHEASTERLY FLOW SOME MORNING FOG EACH DAY COULD OCCUR. ALSO THE
INCREASED INSTABILITY AND HUMIDITY MAY LEAD TO AN ISOLATED SHOWER OR
STORM. NO TRIGGER IN THIS PERIOD FOR ANYTHING MORE THAN ISOLATED TO
PERHAPS SCATTERED SHOWERS AND STORMS, GOING SLIGHT CHANCE ATTM.
MONDAY AND TUESDAY: A COLD FRONT WILL MOVE INTO THE REGION BY
TUESDAY ALONG WITH MOISTURE INCREASING FROM A DECAYING LOW PRESSURE
SYSTEM NEAR OR NORTH OF THE CAROLINAS. THESE TWO FEATURES WILL
RESULT IN THE DEVELOPMENT OF SCATTERED SHOWERS AND THUNDERSTORMS
THAT MAY PRODUCE SOME NEEDED RAINS. ENOUGH SEPARATION WITH THESE
FEATURES WILL LIMIT THE WIDESPREAD HEAVY RAIN THREAT BUT SOME
LOCALIZED DOWNPOURS ARE POSSIBLE. LOW LEVEL MOISTURE AND LIGHT
WINDS MAY RESULT IN ADDITIONAL PERIODS OF PATCHY FOG. RISING 925 MB
TEMPERATURES TO AROUND 20C SHOULD ALLOW INLAND AREAS TO RUN WELL
ABOVE CURRENT NUMERICAL GUIDANCE AND MODELED TWO METER TEMPERATURES
IN THE MID 80`S WITH OVERNIGHT LOWS EACH MORNING IN THE LOW TO MID
60`S. IN TERMS OF ANY SEVERE THREAT WITH THE FRONT, THIS LOOKS
LIMITED AS THE BEST DYNAMICS WILL BE NORTHWEST OF THE MORE
FAVORABLE INSTABILITY ATTM. AREAS THAT DO NOT SEE THE SCATTERED
STORMS WILL SLIP CLOSER TO DROUGHT CONDITIONS AS SHORT TERM DEFICITS
WITH RAINFALL CONTINUE TO GROW.
WEDNESDAY AND THURSDAY: AFTER THE COLD FRONTAL PASSAGE, HIGH
PRESSURE WILL BUILD INTO THE REGION WITH A DRIER AND COOLER AIRMASS.
GOING WITH A LARGER TEMPERATURE SPREAD THAN THE MODELED TWO METER
VALUES. CONSIDERABLE SUNSHINE MAY STILL ALLOW FOR HIGHS INTO THE
70`S AFTER CHILLIER STARTS IN THE 40`S/50`S. THE MAIN CONCERN MAY
END UP BEING FAVORABLE CONDITIONS FOR FIRE SPREAD. RH VALUES AROUND
35% EACH AFTERNOON COUPLED WITH STRONG WEST-NORTHWEST WINDS ARE
POSSIBLE.
&&
.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE,
KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS.
BASICALLY A FAIR WEATHER PATTERN ACROSS THE REGION TONIGHT AND
FRIDAY. HIGH PRESSURE WILL MOVE OFFSHORE TONIGHT AND LITTLE
CLOUDINESS OR WIND IS EXPECTED. THERE IS THE POSSIBILITY FOR FOG
OVERNIGHT WITH THE LOW LEVEL MOISTURE SLOWLY INCREASING ACROSS THE
AREA. WE HAVE KEPT THE FOG FROM THE EARLIER TAFS...AND ADDED A FEW
AREAS SINCE CONDITIONS LOOK RATHER FAVORABLE. THE FOG WILL LIKELY
BURN OFF IN THE 12Z-13Z FRAME FRI WITH VFR AFTER THAT.
OUTLOOK...
FRIDAY NIGHT THROUGH SUNDAY: VFR WITH SOUTH-SOUTHEAST WINDS UNDER 10
KNOTS. SOME MORNING PATCHY LOW FOG POSSIBLE, BEST CHANCES AT RDG,
ACY AND MIV.
MONDAY AND TUESDAY: VFR THROUGHOUT MOST OF THIS PERIOD. SOME
SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE IN THE AFTERNOON AND
EARLY EVENING EACH DAY LEADING TO MVFR OR LOWER CONDITIONS. SOUTHEAST
WIND GUSTS UNDER 15 KNOTS ON MONDAY AND THEN SOUTHWEST WIND GUSTS
AROUND OR UNDER 20 KNOTS ON TUESDAY. PATCHY FOG POSSIBLE MONDAY
MORNING BEFORE 12Z.
&&
.MARINE...
AFTER COORDINATING WITH THE DAY SHIFT, WE HAVE DECIDED TO ISSUE A
DENSE FOG ADVISORY FOR OUR AREA WATERS THROUGH FRIDAY MORNING.
SOME OF THE TRAFFIC CAMS ALONG THE IMMEDIATE COAST LOOKED VERY
FOGGY. LATEST SREF/NARRE AND HRRR GUIDANCE ARE INDICATING THAT THE
FOG SHOULD CONTINUE AND SPREAD THROUGH THE NIGHT. NOT A CONFIDENT
FORECAST OFF OF MONMOUTH AND IN UPPER DELAWARE BAY AND TIMING
MIGHT HAVE TO BE EXTENDED ON FRIDAY AS FLOW REMAINS WEAK AND DEW
POINTS ABOVE WATER TEMPS.
SUB SCA CONDITIONS WITH FAIR WEATHER TONIGHT AND FRIDAY. THERE IS
SOME FOG ACROSS SE NJ/DEL COASTAL AREAS AND INTO SRN DEL BAY AND
EVEN INTO THE AFTERNOON...IT CONTINUES . IT WILL PROBABLY REMAIN INTO
THE EVENING AND PERHAPS BECOME A BIT MORE CONCENTRATED OVERNIGHT. VERY
LIGHT ONSHORE OR UP THE BAY FLOW INTO EARLY TONIGHT THEN
LIGHT/VARIABLE OVERNIGHT.
OUTLOOK...
SEAS AND WINDS ARE LIKELY TO REMAIN BELOW SCA CRITERIA THROUGH MONDAY
WITH SEAS NEAR FIVE FEET MONDAY NIGHT AND TUESDAY AS A COLD FRONT
APPROACHES. WINDS WILL BE MAINLY FROM THE SOUTH AND SOUTHEAST THROUGH
MONDAY THEN FROM THE SOUTHWEST UNDER 15 KNOTS WITH GUSTS UNDER 20
KNOTS, HIGHEST ON TUESDAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 9 AM EDT FRIDAY FOR ANZ431-451>455.
DENSE FOG ADVISORY UNTIL 9 AM EDT FRIDAY FOR ANZ430-450.
&&
$$
SYNOPSIS...GAINES
NEAR TERM...O`HARA
SHORT TERM...O`HARA
LONG TERM...GAINES
AVIATION...GAINES/O`HARA
MARINE...GAINES/GIGI/O`HARA
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
327 PM EDT THU MAY 7 2015
.DISCUSSION...
CURRENT-TONIGHT...MOSTLY SUNNY SKIES WITH LIGHT NWRLY FLOW...THOUGH
EXPECTING NNE FLOW TO DEVELOP ALONG THE EAST COAST AND MOVE SLOWLY
INLAND. WARMER TEMPERATURES THIS AFTERNOON IN THE 80S AREAWIDE.
DRIER CONDITIONS AS WELL WITH DEWPOINT READINGS IN THE 50S TO AROUND
60 DEGREES. AN AREA OF LOW PRESSURE CONTINUES TO SPIN NEAR SOUTH
CAROLINA. DRIER AIR WILL STILL FILTER INTO THE AREA TONIGHT WITH
MOSTLY CLEAR SKIES EXPECTED. LOWS MAINLY IN L/M 60S...THOUGH COULD
SEE SOME U50S ACROSS NW PORTIONS OF VOLUSIA COUNTY.
EARLIER THIS MORNING ADDED A SMALL POP IN FOR LATE THIS
AFTERNOON/EARLY EVENING FOR OKEECHOBEE...ST. LUCIE AND MARTIN
COUNTIES. THIS BECAUSE OF MARGINAL LOW-LEVEL MOISTURE...SEA/LAKE
BREEZE INTERACTIONS AND MID-LEVEL ENERGY. STEERING FLOW FOR ANY
POTENTIAL ACTIVITY WILL BE FROM THE SOUTHWEST TOWARDS THE NORTHEAST.
LOCAL WRF/HRRR MODEL RUNS STILL SUPPORT DEVELOPMENT OF LATE DAY
CONVECTION HERE. FACTORS THAT WOULD INHIBIT DEVELOPMENT INCLUDE DRY
AIR ALOFT AND A SUBSIDENCE INVERSION.
AT THE BEACHES...OCEAN SWELLS FROM THE LOW PRESSURE OFFSHORE WILL
PRODUCE A MODERATE RISK FOR RIP CURRENTS. STRONGEST RIP POTENTIAL
IS LATE THIS AFTERNOON AND EARLY EVENING. SOME ROUGH SURF IS
STILL POSSIBLE FOR THE NRN BREVARD AND VOLUSIA COUNTY BEACHES.
FRI...THE LOW PRESSURE WILL CONTINUE TO SPIN IN PLACE NEAR THE SOUTH
CAROLINA COAST ON THIS DAY. WEAK HIGH PRESSURE WILL BE CENTERED OVER
THE EASTERN GULF. THE PRESSURE GRADIENT WILL BE WEAK ENOUGH FOR BOTH
EAST/WEST COAST SEA BREEZES TO VENTURE INLAND EARLY IN THE AFTERNOON
BACKING WINDS ALONG THE COAST TO E/ESE. LIGHT WNW/NW WINDS WILL
CONTINUE ELSEWHERE. DRIER PRECIPITABLE WATER VALUES WILL SINK SOUTH
ACROSS SOUTHWEST FLORIDA AS WRAP-AROUND MOISTURE FROM THE LOW PUSHES
INTO OUR NORTHERN COVERAGE WARNING AREA. LATEST MODEL RUNS SQUEEZE
OUT VERY LITTLE...IF ANY...QPF SO WILL DISCONTINUE ANY PRECIPITATION
FOR NOW IN THE FORECAST FOR OVER LAND. FUTURE SHIFTS CAN ADD BACK IN
IF THEY FEEL LATE DAY SEA BREEZE COLLISIONS CAN MUSTER
CONVECTION...THOUGH A LOW-LEVEL SUBSIDENCE INVERSION MAY BE TOO HARD
TO OVERCOME. AFTERNOON MIN RH VALUES FALL INTO THE 30S OVER THE
INTERIOR WHICH IS VERY DRY. ANOTHER WARM DAY IN STORE WITH HIGHS IN
THE L80S ALONG THE VOLUSIA/NORTH BREVARD COASTS...MIDDLE 80S FURTHER
SOUTH ALONG THE COAST AND UPPER 80S INLAND FROM THE COAST.
FRIDAY NIGHT-SAT...LOW PRESSURE CENTER IS FORECAST TO BE SLOW
MOVING JUST OFFSHORE THE COAST OF GEORGIA AND SOUTH CAROLINA.
THOUGH QUITE FAR REMOVED FROM THIS SYSTEM...IT WILL STILL EXERT AN
INFLUENCE ON OUR WEATHER. GENERALLY THE SOUTHWEST SIDE OF THIS
TYPE OF SYSTEM HAS LARGE SCALE SUPPRESSION. THE GFS DOES NOT SHOW
ANY DISTURBANCES ROTATING AROUND THE LOW REACHING THIS FAR SOUTH.
THE GFS SHOWS SOMEWHAT HIGHER MOISTURE WRAPPING DOWN INTO EAST
CENTRAL FLORIDA BUT PRECIPITABLE WATER VALUES ARE STILL ONLY 1.3
TO 1.4 INCHES. THE MODEL HAS LITTLE PRECIP GENERATED DURING THIS
TIME PERIOD AND MOS POPS ARE LESS THAN 10 PERCENT. SINCE INHERITED
POPS ACROSS THE NORTH WERE 20 PERCENT...HAVE MAINTAINED A SLIGHT
AFTERNOON POP THERE...BUT TRIMMED THE AREAL COVERAGE BACK
SLIGHTLY. ACTUALLY...THE LOW LEVEL CYCLONIC FLOW AND SLIGHTLY
INCREASED LOW LEVEL MOISTURE MIGHT BE MORE OF A SIGNAL OF
CONSIDERABLE STRATUS DURING THE OVERNIGHT/MORNING.
SUN-WED...(PREVIOUS DISCUSSION) THE ATLC RIDGE AXIS WILL REBUILD
OVER FL STRAITS AND LIFT STEADILY NWD THRU EARLY NEXT WEEK AS THE
CAROLINA LOW DRIFTS INTO THE MID ATLC REGION AND BECOMES ABSORBED
BY A LARGER SHORT WAVE FRONTAL TROF. REGIONAL WINDS THRU THE
H100-H70 LYR WILL SHIFT TO THE S/SE AS A RESULT...TAPPING AN
AIRMASS THAT IS STRUGGLING TO MAINTAIN HIGH ENOUGH LOW/MID LVL
HUMIDITY TO SUPPORT PRECIP. RAP ANALYSIS SHOWS H100-H70 RH VALUES
REMAIN LARGELY AOB 70PCT...THOUGH A BAND OF H85-H50 RH AOA 50PCT
EXTENDING FROM HONDURAS TO THE CENTRAL BAHAMAS COULD MAKE UP FOR
THE DRIER LOW LVLS.
WILL KEEP PRECIP IN THE FCST THRU THE MIDDLE OF NEXT WEEK...BUT
LIMITING CHANCES TO THE 20-30PCT RANGE AS THE INCREASING INFLUENCE
OF THE ATLC RIDGE WILL TEND TO BLOCK OR CANCEL OUT ANY MID/UPR LVL
DYNAMIC SUPPORT. DVLPG ONSHORE FLOW WILL KEEP TEMPS NEAR OR SLIGHTLY
ABV CLIMO AVG...AFTN MAXES IN THE M/U80S... MRNG MINS IN THE
U60S/L70S.
&&
.AVIATION...MAINLY VFR. NW WINDS EXCEPT NNE ALONG THE COAST LATER
THIS AFTERNOON AS A SEA BREEZE MARCHES SLOWLY INLAND. STILL COULD
SEE AN ISOLD LATE DAY/EARLY EVENING STORM NEAR LAKE OKEECHOBEE.
INTERESTS NEAR KOBE-KFPR-KSUA SHOULD REMAIN AWARE AS LOCAL MODEL
RUNS STILL KEEN ON THIS.
&&
.MARINE...CURRENT-TONIGHT...WINDS/SEAS WILL CONTINUE TO DECREASE
SLOWLY AS THE LOW VENTURES FURTHER NORTH TOWARD SOUTH CAROLINA AWAY
FROM ECFL. WEAK HIGH PRESSURE WILL BUILD IN FROM THE NORTH AND WEST.
AT 4PM/20Z LIKELY TO CONTINUE THE SCA OFFSHORE NORTH OF SEBASTIAN
INLET BASED ON RECENT BUOY 41009 OBS FOR WINDS/SEAS. CAUTIONARY
STATEMENTS LIKELY TO CONTINUE FOR THE SOUTHERNMOST OFFSHORE LEG AND
POSSIBLY NEAR SHORE FOR NORTH OF SEBASTIAN INLET. JUST NOT SEEING
ENOUGH IMPROVEMENT TO TAKE THESE STATEMENTS AWAY. NW/N WINDS WILL
BACK TO WESTERLY OVERNIGHT.
FRI...LOW PRESSURE CONTINUES TO SPIN IN PLACE OFF OF THE SOUTH
CAROLINA COAST WITH WEAK HIGH PRESSURE CENTERED OFF OF THE FLORIDA
WEST COAST. W/NW WINDS WILL FALL TO AROUND 10 KTS OR LESS IN THE
AFTERNOON. THE PRESSURE GRADIENT WILL BE WEAK ENOUGH FOR THE EAST
COAST SEA BREEZE TO DEVELOP EARLY IN THE AFTERNOON BACKING WINDS
ALONG THE COAST TO E/ESE. SEAS FALLING TO 2-4 FT NEAR SHORE AND 4-5
FT OFFSHORE.
WEEKEND...LOW PRESSURE CENTER IS STILL FORECAST TO BE SLOW MOVING
NEAR THE SOUTH CAROLINA COAST. THE SYSTEM MAY STRENGTHEN SOME BUT
EXPECT IT WILL LIKELY BECOME MORE COMPACT...SO THE MAIN PERIPHERAL
IMPACTS SHOULD SHIFT NORTH OF OUR WATERS. THE MODELS SHOW ATLANTIC
SURFACE RIDGE NOSING BACK IN ACROSS THE SOUTH HALF OF THE
PENINSULA BY SUNDAY. WINDS OUT OF THE WEST ON SAT SHOULD EASE
ENOUGH FOR A SEA BREEZE CIRCULATION IN THE AFTERNOON/EVENING THEN
THE GRADIENT FLOW WILL BECOME SOUTHERLY SAT NIGHT AND SUNDAY.
SPEEDS ARE FORECAST TO BE 15 KNOTS OR LESS.
&&
.FIRE WEATHER...REMAINDER OF AFTERNOON...MIN RHS STILL FORECAST TO
DROP INTO THE L/M 30S THIS AFTERNOON ACROSS THE NRN INTERIOR WITH NW
20 FOOT WINDS TO AROUND 10 MPH.
FRI...THE LOW-LEVELS REMAIN DRY WITH AFTERNOON RH VALUES PLUMMETING
AGAIN INTO THE L/M 30S ACROSS THE I-4 CORRIDOR. THE PRESSURE
GRADIENT WILL BE LIGHT ENOUGH TO ALLOW FOR THE EAST COAST SEA BREEZE
TO DEVELOP AND MOVE SLOWLY INLAND DURING THE AFTERNOON. NW 20 FT
WINDS 5-10 MPH. HEADLINES STILL NOT NECESSARY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 62 83 66 85 / 0 20 10 20
MCO 65 88 66 90 / 0 10 0 20
MLB 64 85 65 86 / 0 10 10 20
VRB 62 86 64 87 / 10 10 10 20
LEE 64 86 67 88 / 0 20 0 20
SFB 64 88 67 89 / 0 20 10 20
ORL 66 88 67 90 / 0 20 0 20
FPR 62 86 65 87 / 20 10 10 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR VOLUSIA-
BREVARD COUNTY LINE TO SEBASTIAN INLET 20-60 NM-FLAGLER BEACH TO
VOLUSIA-BREVARD COUNTY LINE 20-60 NM.
&&
$$
SHORT TERM...SEDLOCK
LONG TERM....LASCODY
AREA FORECAST DISCUSSION
NWS LINCOLN IL
300 PM CDT THU MAY 7 2015
.SHORT TERM...(TONIGHT)
ISSUED AT 259 PM CDT THU MAY 7 2015
SCATTERED SHOWERS AND THUNDERSTORMS OVER MO AND IA INTO INTO THE MS
RIVER VALLEY OF IL WILL SPREAD NE ACROSS CENTRAL IL LATE THIS
AFTERNOON AND INTO TONIGHT. MODELS HAVE THE CONVECTION WEAKENING
AFTER SUNSET WITH LOSS OF INSTABILITY AND BECOMING MORE ISOLATED IN
EASTERN IL OVERNIGHT SO HAVE TRENDED POPS FROM 50-60% IN WESTCENTRAL
IL LATE THIS AFTERNOON AND TONIGHT TO ISOLATED IN EASTERN IL BY
OVERNIGHT. SPC HAS MARGINAL RISK WEST OF A PEORIA TO JACKSONVILLE
LINE WHERE CAPES PEAK FROM 1200-1800 J/KG THROUGH 00Z/7 PM. MAINLY
SMALL HAIL POSSIBLE THIS AFTERNOON AND EARLY EVENING UNTIL SUNSET.
GETTING A FEW HALF TO THREE QUARTER INCH SIZE HAIL REPORTS PAST HOUR
OVER NE MO AND FUNNEL CLOUD REPORT NEAR HANNIBAL MO. COLD FRONT JUST
NW OF IA INTO CENTRAL KS TO PUSH INTO SE IA AND NW MO BY SUNRISE
FRI. MILD LOWS MOSTLY IN THE MID 60S TONIGHT WITH BREEZY SSW WINDS
10-20 MPH AND GUSTS OF 20-35 MPH THIS AFTERNOON DIMINISHING TO
AROUND 10 MPH AFTER SUNSET.
&&
.LONG TERM...(FRIDAY THROUGH THURSDAY)
ISSUED AT 259 PM CDT THU MAY 7 2015
AN ACTIVE AND UNSEASONABLY MILD WEATHER PATTERN IS EXPECTED TO
PERSIST ACROSS CENTRAL AND SOUTHEAST ILLINOIS THROUGH MONDAY. MAIN
FORECAST CONCERN REVOLVES AROUND SHOWER/THUNDERSTORM TIMING AND
INTENSITY THROUGH MONDAY. UNFORTUNATELY, THE LIMITS OF
PREDICTABILITY WITH CONVECTIVE WEATHER MAKE THE DETAILS TOUGH TO
PINPOINT TOO FAR OUT.
THE FRONTAL BOUNDARY THAT CURRENTLY EXTENDS THROUGH THE UPPER
MIDWEST AND INTO THE SOUTHERN PLAINS WILL CONTINUE TO MAKE SLOW
EASTWARD PROGRESS THE NEXT FEW DAYS, EVENTUALLY CLEARING THE AREA
ON MONDAY. THE PASSAGE OF THIS FRONT WILL END THE UNSETTLED
WEATHER PATTERN AND PUSH TEMPERATURES BELOW NORMAL FOR MUCH OF
NEXT WEEK.
EXPECT A DIURNALLY INDUCED MAXIMUM COVERAGE OF SHOWERS/STORMS INTO
SATURDAY AS THERE DOES NOT APPEAR TO BE A SIGNIFICANT UPPER LEVEL
FEATURE TO FOCUS PRECIPITATION BY THEN, AND NO SIGNIFICANT NOCTURNAL
LOW LEVEL JET IS EXPECTED EITHER. THE SEVERE THREAT THROUGH SATURDAY
ALSO LOOKS TO BE SPOTTY AT BEST GIVEN WEAK SHEAR PROFILES AND MOSTLY
MODEST INSTABILITY. WHILE THE INSTABILITY IS LIKELY TO BECOME MUCH
BETTER BY SATURDAY AFTERNOON, PEAKING IN EXCESS OF 1500 J/KG, SHEAR
PROFILES STILL DON`T SUPPORT ORGANIZED SEVERE WEATHER.
THE CUTOFF UPPER LOW, CURRENTLY ALONG THE CALIFORNIA COAST, WILL
FINALLY GET MOVING AND PASS WEST/NORTH OF THE FORECAST AREA SUNDAY
INTO MONDAY. THIS IS THE FEATURE THAT WILL EVENTUALLY DRIVE THE
SURFACE FRONT THROUGH THE AREA. ITS APPROACH/PASSAGE WILL ALSO
PROVIDE ENHANCED SHEAR PROFILES LOCALLY (TO GO ALONG WITH GOOD
DIURNAL INSTABILITY) IN THE WEST ON SUNDAY AND AREAWIDE FOR MONDAY.
THESE DAYS WILL BE OUR MOST LIKELY TIME FOR SEVERE STORMS,
ESPECIALLY MONDAY.
ONCE THE COLD FRONT CLEARS THE AREA MONDAY, QUIET AND COOLER WEATHER
WILL BE WITH US FOR MUCH OF THE WEEK. DAILY HIGH TEMPERATURES THAT
HAD BEEN MAINLY IN THE 80S THE PAST SEVERAL DAYS, WILL FALL INTO THE
60S, WHICH IS BELOW NORMAL FOR EARLY/MID MAY. THE COOLER/QUIETER
WEATHER WILL ARRIVE ALONG WITH A STRONG CANADIAN AREA OF HIGH
PRESSURE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1259 PM CDT THU MAY 7 2015
HAVE VCTS AT PIA AND SPI STARTING AT 23Z INTO MID EVENING AND AT
BMI AND DEC STARTING AT 01Z FOR THIS EVENING PER LATEST HRRR AND
RAP MODEL RUNS. THESE MODELS KEEP CMI DRY NEXT 24 HOURS PROTECTED
BY SURFACE AND UPPER LEVEL RIDGE IN THE SOUTHEAST STATES. ISOLATED
TO SCATTERED SHOWERS AND THUNDERSTORMS LIKELY WILL DEVELOP FRIDAY
AFTERNOON MAINLY AFTER 18Z/FRI WITH BEST CHANCES OVER WESTERN
AIRPORTS AGAIN CLOSER TO APPROACHING FRONTAL BOUNDARY MOVING INTO
SE IA AND NW MO FRIDAY MORNING. BREEZY SSW WINDS 14-20 KTS WITH
GUSTS 24-30 KTS THIS AFTERNOON TO DIMINISH TO 5-10 KTS AFTER
SUNSET OUT OF THE SOUTH AND THEN SW AROUND 10 KTS FRI MORNING.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...BAK
AVIATION...07
AREA FORECAST DISCUSSION
NWS LINCOLN IL
100 PM CDT THU MAY 7 2015
.UPDATE...
ISSUED AT 1045 AM CDT THU MAY 7 2015
FORECAST LOOKS ON TRACK TODAY AS ONLY MINOR ADJUSTMENTS NEEDED.
ANOTHER WARM AND RATHER HUMID SUMMER LIKE DAY EXPECTED WITH HIGHS
IN THE LOW TO MID 80S. HAVE 20-40% CHANCE OF SHOWERS AND
THUNDERSTORMS DURING MID/LATE AFTERNOON FROM LINCOLN WESTWARD WITH
HIGHEST POPS WEST TOWARD THE MS RIVER VALLEY. SOUTH BREEZES
OF 10-20 MPH WITH GUSTS 20-30 MPH EXPECTED AGAIN TODAY AND WINDS
ALREADY GUSTING IN THE 20S AT LATE MORNING WEST OF I-57.
&&
.SHORT TERM...(TODAY)
ISSUED AT 335 AM CDT THU MAY 7 2015
A COLD FRONTAL BOUNDARY ORIENTED NORTH-SOUTH ACROSS THE NORTHERN AND
CENTRAL PLAINS EARLY THIS MORNING WILL APPROACH SLOWLY THROUGH THE
DAY WHILE A LARGE SCALE TROUGH OVER THE WESTERN U.S. AND RIDGE OVER
THE EASTERN U.S. PROVIDE FOR GENERAL SOUTHWESTERLY FLOW ACROSS THE
CENTRAL UNITED STATES. INCREASING LOW AND MID-LEVEL MOISTURE WILL
CREATE ENOUGH INSTABILITY OVER WESTERN PORTIONS OF THE STATE FOR
ISOLATED TO SCATTERED THUNDERSTORMS BY AFTERNOON...ALTHOUGH MOST OF
THE CONVECTIVE ACTIVITY SHOULD FOCUS FARTHER WEST CLOSER TO THE
FRONTAL BOUNDARY EDGING INTO IA/MO. WARM HIGH TEMPERATURES WILL
CONTINUE TODAY WITH HIGHS IN THE MID 80S. EXPECT BREEZY SOUTH WINDS
10-15 MPH.
EARLY MORNING A FEW SHOWERS ARE POSSIBLE AS AN INITIAL UPPER LEVEL
DISTURBANCE TRANSLATES FROM SW MO INTO WESTERN IL MAINLY WEST OF THE
ILLINOIS RIVER.
.LONG TERM...(TONIGHT THROUGH WEDNESDAY)
ISSUED AT 335 AM CDT THU MAY 7 2015
NOT A LOT OF CHANGES IN THE SHORT AND MEDIUM RANGE FORECASTS WITH
THE MODELS MAINTAINING THE SOUTHWESTERLY FLOW PATTERN THROUGH THE
WEEKEND. STARTING TO SEE DISPARITY IN THE LONGER RANGE ON THE OTHER
SIDE OF SUNDAY/MONDAY WITH THE PROGRESSION OF THE UPPER WAVE. GFS
KEEPS THE LOW WRAPPED UP AND CUT OFF, POTENTIALLY INTRODUCING MORE
AND COOLER AIRMASS INTO THE MIDWEST IN THE WAKE OF IT...WHILE THE
ECMWF IS OPENING THE LOW AND FOR NOW, REMAINING PRETTY CONSISTENT.
STORM SYSTEM TO THE WEST SLOWLY APPROACHING THE FA TODAY WILL SPREAD
PRECIP OVER THE FA FROM WEST TO CENTRAL MAINLY TONIGHT...AND
TOMORROW BECOMING MORE WIDESPREAD ACROSS THE AREA AS THE FRONT
SETTLES INTO THE REGION. LOW OVER THE PAC NW DIGGING IN TODAY AND
TONIGHT OVER THE DESERT SW AND ESTABLISHING A SOUTHWESTERLY FLOW
PATTERN INTO THE MIDWEST. A SERIES OF SMALL WAVES ROTATING AROUND
THE MAIN TROF TO THE SOUTHWEST WILL MOVE ALONG INVOF THE BOUNDARY
WITH THE BOUNDARY PROVIDING FOCUS FOR SHOWERS AND THUNDERSTORMS.
EXPECTING TO KEEP THE PATTERN WET THROUGH THE WEEKEND, THOUGH THERE
WILL LIKELY BE BREAKS IN SOME OF THE RAINFALL. FINALLY SEE THE MAIN
UPPER LOW LIFT OUT OF THE SW SUN NIGHT/MONDAY...WITH A STORMY
OUTLOOK FOR THE SFC AS A TRUE COLD FRONT PUSHES THROUGH THE REGION.
TIMING FOR THE BOUNDARY ON MONDAY WILL BE CLOSELY WATCHED AS THERE
IS A DECENT CHANCE FOR SOME OF THE STORMS TO BECOME SEVERE WITH A
MIX OF INSTABILITY WITH STRONG SOUTHERLY FLOW AHEAD OF THE
SYSTEM...AND DEEP LAYER SHEAR WITH THE UPPER LOW LIFTING OUT.
COOLER TEMPS AND DRY WEATHER EXPECTED FOR TUE/WED AS THE AIRMASS
SHIFTS EAST AND COLDER AIR FILTERS INTO THE REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1259 PM CDT THU MAY 7 2015
HAVE VCTS AT PIA AND SPI STARTING AT 23Z INTO MID EVENING AND AT
BMI AND DEC STARTING AT 01Z FOR THIS EVENING PER LATEST HRRR AND
RAP MODEL RUNS. THESE MODELS KEEP CMI DRY NEXT 24 HOURS PROTECTED
BY SURFACE AND UPPER LEVEL RIDGE IN THE SOUTHEAST STATES. ISOLATED
TO SCATTERED SHOWERS AND THUNDERSTORMS LIKELY WILL DEVELOP FRIDAY
AFTERNOON MAINLY AFTER 18Z/FRI WITH BEST CHANCES OVER WESTERN
AIRPORTS AGAIN CLOSER TO APPROACHING FRONTAL BOUNDARY MOVING INTO
SE IA AND NW MO FRIDAY MORNING. BREEZY SSW WINDS 14-20 KTS WITH
GUSTS 24-30 KTS THIS AFTERNOON TO DIMINISH TO 5-10 KTS AFTER
SUNSET OUT OF THE SOUTH AND THEN SW AROUND 10 KTS FRI MORNING.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...07
SHORT TERM...ONTON
LONG TERM...HJS
AVIATION...07
AREA FORECAST DISCUSSION
NWS TOPEKA KS
410 PM CDT Thu May 7 2015
.SHORT TERM...(This Evening through Friday)
Issued at 405 PM CDT THU MAY 7 2015
Challenging forecast again tonight with somewhat disorganized
convection this evening and overnight. Band of stronger
thunderstorms forming in weak convergence and max instability axis
from central KS to southeast Nebraska. 0-6 km bulk shear in that
area in the 30 kt range while 0-1 km shear is weak. Storms could
display some organization with hail and wind the main severe
threats. Very heavy rain may also be a concern with slow storm
movement and the potential for some training. Showers and isolated
thunderstorms in east central KS in an area of weak isentropic lift
and have persisted for awhile today and are not going away by late
afternoon. RAP and last few HRRR runs have done alright with
development along boundary/instability axis and have this area
persist and then move southeast overnight. Heavy rain will be the
main threat later tonight.
Challenge for Friday is how much remnant showers/storms will occur
in the morning. Believe best chances of persistence into the
morning will be in east central Kansas. Several models are then
supportive of a shortwave impulse coming out of the southwest moving
into forecast area around early evening on Friday.
.LONG TERM...(Friday Night through Thursday)
Issued at 405 PM CDT THU MAY 7 2015
By Friday evening severe convection will form along the dry line
across far southwest KS. That area of convection will likely expand
in coverage as it moves northeastward through the overnight hours.
At the surface a warm front will begin to lift back northward into
the day Saturday. Convection looks to generally track along this
front passing through most of southern KS. Lapse rates decrease
during the evening hours as mid to upper 60 dewpoints spread into
the southern half of the forecast area. This places cape values in
the 1500-2500 j/kg valid at 00Z. Models agree that the cape will
decrease, but remains somewhat modest as the deep layer shear
increases to around 35 kts. The NAM is the most aggressive with an
increasing low level jet developing over southern KS as the storms
approach the area. Given the parameters in place strong to severe
storms are possible. The models are fairly consistent in bringing a
decent amount of QPF through the area by 12Z Sat. Flooding will
definitely be a concern especially given the recent rainfall and
saturated ground at some locations. There is a chance for a dry
period during the day Sat before the next round associated with the
main mid level low ejecting out of the Rockies. The chance for
severe storms overnight Saturday is greater across the area given
the dry line will be further east into central KS. Also, the deep
layer shear looks to be closer to 50 kts and the cape remains as
high as 2000 j/kg. Low level jet increases again leading to wind
profile favorable for supercells and possibly tornadoes. This threat
may diminish during the early morning hours as depicted by the NAM,
which barely brings QPF into the area overnight. The dry line
continues eastward as the main mid level low lifts through NE and
SD. By the time the atmosphere destabilizes the dry line will be
located somewhere in far eastern KS where storms are likely to form.
The vertical wind profile appears to be more unidirectional out of
the southwest, which is more parallel to the boundary possibly
leading to more cell interaction. So discrete supercells initially
may quickly transition into a cluster or line, and there is plenty
of cape and deep layer shear for these storms to be severe Sun
afternoon.
The upper level system finally begins to lift northeast late Sunday
into Monday and becomes and open wave by Tuesday over the Upper
Mississippi Valley. Dry and stable conditions are left in its wake,
which will be very needed by this point as the area needs to dry out
a bit before the next system develops. The upper levels will
transition to a more zonal flow pattern over the Central Plains.
Meanwhile, the next trough will begin to set up over the Western
CONUS. At this point, it could be a similar upper level pattern
developing as has recently been in place. However, at this point,
it doesn`t appear moisture recovery, necessary for as wet of a
pattern, will be in place at least through Thursday night. A quick
upper level shortwave may be ejected out of the Southern Rockies in
the afternoon time frame on Wednesday and possibly interact with a
weak warm boundary near the KS/NE border. There could be some
isolated convection flare up, but at this point it doesn`t appear to
be too noteworthy of an event. Will have to stay tuned as this is
too far out to have much confidence at this point in how exactly it
will play out.
&&
.AVIATION...(For the 18Z TAFs through 18Z Friday Afternoon)
Issued at 1242 PM CDT THU MAY 7 2015
Deck of MVFR stratus hanging in over central KS and KMHK. Expect
this to lift early this afternoon. Thunderstorm chances begin
again by mid to late afternoon at MHK and early evening farther
east at FOE and TOP. Other than in thunderstorms, could get
another stratus deck in later tonight with MVFR ceilings.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GDP
LONG TERM...Drake/Sanders
AVIATION...GDP
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1126 AM CDT THU MAY 7 2015
.DISCUSSION...
AS EXPECTED WE ARE SEEING ISOLD TO WIDELY SCATTERED SHWRS POPPING
UP AREA WIDE LATE THIS MORNING AND THUS HAVE EXPANDED POPS TO
INCLUDE ALL OF OUR REGION FOR THE REMAINDER OF THIS MORNING. AS
INSTABILITY CONTINUES TO INCREASE LATER TODAY...EXPECT THAT SOME
ISOLD TSTMS WILL ALSO BE POSSIBLE WITH EXISTING OUTFLOW BOUNDARIES
STILL PRESENT FROM EARLIER CONVECTION WITH DECAYING MCS OVER OUR
FAR NRN TIER COUNTIES. KEPT POPS UNCHANGED FOR THIS AFTERNOON WITH
LOW CHANCE FOR MOST AREAS AND JUST SLIGHT CHANCE OVER OUR FAR ERN
SECTIONS. THE ONLY OTHER UPDATE FOR THIS MORNING WAS TO RAISE DEW
POINTS AS WE ARE RUNNING A FEW DEGREES HIGHER THAN PREVIOUS
FORECAST INDICATED. OTHERWISE...THE FORECAST IS IN GOOD SHAPE.
UPDATED PRODUCTS HAVE ALREADY BEEN SENT. /19/
&&
.PREV DISCUSSION... /ISSUED 448 AM CDT THU MAY 7 2015/
DISCUSSION...
IR AND RADAR MOSAICS SHOWING A DECAYING MCS ACROSS EASTERN
OKLAHOMA INTO NORTH CENTRAL TEXAS. THE SYSTEM IS DECAYING BECAUSE
LOW LEVEL INFLOW INTO THE SYSTEM IS MUCH WEAKER COMPARED TO A MUCH
STRONGER LOW LEVEL JET JUST TO THE WEST OF THE SYSTEM. THE
TERMINAL FORECAST PACKAGE FOR TODAY/THIS EVENING WILL BE TIED TO A
REMNANT OUTFLOW BOUNDARY PRODUCED BY THIS LARGE CLUSTER OF
THUNDERSTORMS. SHORT TERM PROGS ARE NOT HANDLING THIS SYSTEM VERY
WELL AT ALL...BUT THE HRRR DOES AT LEAST ACKNOWLEDGE THE REMNANT
BOUNDARY WHICH SHOULD SET UP WEST TO EAST ACROSS OUR NORTHERN
ZONES TODAY. THUS...WITH DAYTIME HEATING AND INSTABILITY...THE
BOUNDARY SHOULD SERVE AS A FOCUS FOR SCATTERED CONVECTION WHICH
COULD INFLUENCE AT THE VERY LEAST THE TXK TERMINAL. IF THE
BOUNDARY WAS TO PUSH FURTHER SOUTH TOWARDS THE I-20
CORRIDOR...THEN OUR NE TX TERMINALS WOULD BE IN PLAY FOR AFTERNOON
CONVECTION.
FOR NOW...WILL JUST MAKE MENTION OF VCTS AT THE TXK TERMINAL AND
KEEP ALL OTHER TERMINALS OUT OF THIS MENTION. NOT SAYING OUR OTHER
TERMINALS WILL BE COMPLETELY VOID OF TSRA TODAY BUT CHANCES DO NOT
WARRANT A MENTION ATTM.
MVFR/IFR CEILINGS HAVE BEEN CONFINED TO OUR TYR TERMINAL ONLY AS
OF THIS DISCUSSION EARLY THIS MORNING BUT STILL EXPECTING TO SEE
THIS CLOUD COVER MOVE INTO AT LEAST THE LFK/GGG TERMINALS. THESE
CONDITIONS SHOULD LIFT AND/OR SCATTER OUT BY LATE MORNING/EARLY
AFTERNOON. SHOULD SEE A LITTLE MORE IN THE WAY OF MVFR/IFR
CEILINGS ONCE AGAIN OVERNIGHT TONIGHT INTO EARLY FRIDAY MORNING.
13
PREV DISCUSSION... /ISSUED 436 AM CDT THU MAY 7 2015/
DISCUSSION...
MCS OVER N TX HAS FINALLY PICKED UP SOME FORWARD MOMENTUM OVER
THE LAST COUPLE OF HRS. LATEST RADAR LOOPS INDICATE PORTIONS OF
THE MCS NORTH OF THE RED RIVER HAVE MORE OF A NELY MOVEMENT AND
ARE BEGINNING TO DISSIPATE...SEGMENT NEAR AND SOUTH OF THE RED
RIVER IS MOVING MORE EASTERLY AND IS A BIT MORE ORGANIZED. IR
IMAGERY OVER THE LAST FEW HRS ALSO INDICATE THAT CLOUD TOPS ARE
WARMING WHICH ALSO SUGGESTS AN OVERALL DECREASE IN INTENSITY.
THESE TRENDS ARE EXPECTED TO CONTINUE AS THE COMPLEX APPROACHES.
THE MCS SHOULD REACH PORTIONS OF SE OK/NE TX NORTH OF I-30 BEFORE
DISSIPATING AND/OR MOVING NE OF THE AREA. MOST OF THE MODELS HAVE
NOT HANDLED THIS COMPLEX PARTICULARLY WELL...ALTHOUGH THE HRRR
SEEMS TO HAVE THE BEST SOLUTION COMPARED TO CURRENT CONDITIONS
AND LATEST TRENDS. INCLUDED UPDATED POP/WX GRIDS FOR THE PERIOD
BEFORE 12Z THIS MORNING.
IN REGARDS TO RAIN CHANCES TODAY...THE MODELS ARE PRACTICALLY
WORTHLESS. NONE OF THEM INITIALIZED PARTICULARLY WELL IN THEIR
HANDLING OF THE ONGOING N TX MCS. THE 00Z NAM AND A COUPLE OF HI-
RES MODELS DEVELOP A COMPLEX ACROSS W TX AND SWEEP IT QUICKLY
EASTWARD WITH QUITE A ROBUST LOOKING MCS FROM TYLER TX TO PRESCOTT
AR AT 00Z THIS EVENING. THE BIGGEST PROBLEM WITH THIS FORECAST IS
THAT IT RESULTS FROM TSTMS SUPPOSEDLY ALREADY ONGOING ACROSS W TX
WHERE NOTHING IS ACTUALLY OCCURRING. THE GFS IS ILL-DEFINED WITH
WIDESPREAD QPF EVERYWHERE AND THE ECMWF APPEARS TO BE SUFFERING
SOME CONVECTIVE FEEDBACK ISSUES.
SINCE THE OVERALL SYNOPTIC PATTERN IS LARGELY UNCHANGED FROM
WEDNESDAY...A PERSISTENCE FORECAST WILL ONCE AGAIN BE USED TODAY
AND FRIDAY. CHANCES FOR CONVECTION MAY BE A BIT HIGHER TODAY IF
THE SEGMENT OF THE ONGOING MCS SOUTH OF THE RED RIVER CAN MAINTAIN
ITSELF LONG ENOUGH TO TAKE ADVANTAGE OF DIURNAL HEATING TODAY.
EVEN IF THE MCS DOES DISSIPATE...A RESIDUAL OUTFLOW BOUNDARY COULD
PROVIDE A FOCUS FOR SHWRS/TSTMS THIS AFTERNOON AND EARLY THIS
EVENING. POTENTIAL WILL EXIST ONCE AGAIN FOR CONVECTION THAT
DEVELOPS FARTHER WEST OVER OK/TX TO MOVE INTO THE ARKLATEX EARLY
FRIDAY MORNING...BUT WILL GENERALLY KEEP POPS LESS THAN 30 PERCENT
AT THIS TIME. AFTERNOON HIGH TEMPERATURES WILL CONTINUE TO RUN IN
THE LOW TO MID 80S AREAWIDE.
SATURDAY WILL LIKELY BE VERY SIMILAR TO TODAY AND FRIDAY.
HOWEVER...A LARGE AND STRONG UPPER TROUGH WILL BE MOVING EWD
THROUGH THE FOUR CORNERS REGION BEFORE EJECTING NEWD INTO KS/NE BY
EARLY SUNDAY MORNING. THE INCREASED LARGE SCALE ASCENT SHOULD ALSO
RESULT IN MUCH HIGHER RAIN CHANCES BEGINNING DURING THE DAY
SATURDAY ACROSS THE NW HALF OF THE CWA.
BEST CHANCES FOR WIDESPREAD...AND POSSIBLY LOCALLY HEAVY
RAINFALL...WILL BE LATE SUNDAY THROUGH MONDAY. A COLD FRONT WILL
BEGIN TO APPROACH AND EVENTUALLY MOVE ACROSS THE AREA AS THE AXIS
OF THE UPPER TROUGH SWINGS EAST ACROSS THE SRN PLAINS. SEVERE
WEATHER WILL BE A POSSIBILITY DURING THIS TIME FRAME...DAMAGING
WINDS AND HAIL SHOULD BE THE PRIMARY THREATS. THE SURFACE FRONT
MAY STALL SOMEWHERE JUST SOUTH OF THE CWA BY TUESDAY. MEDIUM
RANGE MODELS SUGGEST THE 850 MB FRONT WILL STALL SOMEWHERE NEAR
I-20. THIS WILL KEEP SHWRS/TSTMS THROUGH IN THE FORECAST THROUGH
THE EXTENDED PERIODS MAINLY SOUTH OF I-30.
09
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 84 69 85 71 / 30 20 30 30
MLU 86 67 87 70 / 20 10 20 10
DEQ 81 68 82 68 / 30 30 30 40
TXK 83 68 83 69 / 30 20 30 30
ELD 85 68 85 69 / 20 20 20 20
TYR 83 69 84 69 / 30 20 30 30
GGG 84 69 85 70 / 30 20 30 30
LFK 86 70 87 71 / 30 20 30 30
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
19
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1232 PM CDT THU MAY 7 2015
.UPDATE...
ISSUED AT 1232 PM CDT THU MAY 7 2015
UPDATED FOR THE NEW 18Z AVIATION DISCUSSION BELOW.
UPDATE ISSUED AT 1014 AM CDT THU MAY 7 2015
WE HAVE MADE SOME ADJUSTMENTS THIS MORNING TO LOWER POPS...MAINLY
FAR EAST WHERE NO RAIN HAS FALLEN YET. OVERALL...AREA RADARS SHOW
SCATTERED SHOWERS WITH HIGHEST COVERAGE OVER OUR NORTHWEST ZONES
AS OF 15Z. SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS AFTERNOON
BUT COVERAGE MAY NOT BE WIDESPREAD. WE LEFT POPS HIGH THOUGH AS WE
DO EXPECT TO SEE SHOWERS AND STORMS MOVE THROUGH...BUT THERE WILL
BE BREAKS AT TIMES.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 355 AM CDT THU MAY 7 2015
AT 345 AM...WE SAW ONE AREA OF SHOWERS EXITING THE INTERNATIONAL
BORDER REGION...WHILE A NEW AREA OF SHOWERS AND POSSIBLE STORMS
WAS MOVING INTO THE SOUTHERN CWA. AN AREA OF PARTIAL CLEARING HAD
DEVELOPED IN BETWEEN THOSE TWO AREAS OF PRECIPITATION.
TEMPERATURES RANGED FROM THE 40S NEAR LAKE SUPERIOR TO THE LOWER
60S IN THE SOUTHERN PORTION OF THE CWA.
THE FOCUS FOR THE PERIOD FROM TODAY THROUGH FRIDAY...AND ESPECIALLY
FOR TODAY...IS TRYING TO RESOLVE THE OVERALL PRECIPITATION POTENTIAL
AND AMOUNTS. AN ANALYSIS OF THE HRRR/RAP/WRF AND THE NAM/GFS/ECMWF
INDICATED NONE OF THE MODELS HAD A GOOD HANDLE ON THE CURRENT
PRECIPITATION AREA...WITH MOST OF THE MODELS TOO SLOW WITH THE
CURRENT SHOWERS MOVING INTO THE SOUTHERN CWA. OVERALL...THINK THE
MODELS DO CATCH UP AND THE TREND FOR INCREASING PRECIPITATION
TODAY SOUNDS LIKE A REASONABLE SCENARIO. WILL GENERALLY HAVE HIGH
POPS ACROSS THE CWA TODAY AND TONIGHT...WITH CHANCES INCREASING
THROUGHOUT THE MORNING TODAY. HIGH RESOLUTION MODELS SUCH AS THE
4KM NMM WRF AND THE HRRR INDICATE THE MODE OF PRECIPITATION SHOULD
BECOME MORE CELLULAR DURING THE DAY. SPC HAS A PORTION OF OUR AREA
IN THE MARGINAL SEVERE WEATHER THREAT AREA...AND THAT SEEMS
REASONABLE GIVEN THE BETTER CHANCE FOR SEEING SOME DAYTIME HEATING
AND PARTIAL SUNSHINE IN THE SOUTHERN PORTION OF THE CWA.
PRECIPITABLE WATER VALUES THIS MORNING ARE GENERALLY IN THE 1.2
INCH RANGE. A FORMIDABLE LLJ OF UP TO 50 KT WAS EVIDENT THROUGHOUT
THE PLAINS AND UPPER MIDWEST.
TODAY...WILL GO WITH FAIRLY HIGH POPS. PRECIPITATION WILL COME IN
WAVES AND INCREASE THROUGHOUT THE DAY. HIGHS SHOULD GENERALLY BE
IN THE 70S...ALTHOUGH SOME 60S ARE POSSIBLE IN SPOTS...WITH 40S
AND 50S NEAR THE LAKE. COULD BE SOME STRONG THUNDERSTORMS DURING
THE LATTER PORTION OF THE DAY...AND POSSIBLY AN ISOLATED SEVERE
THUNDERSTORM ACROSS THE SOUTHEAST HALF OF THE CWA.
TONIGHT...SHOWERS AND THUNDERSTORMS WILL BE LIKELY. A FEW STRONG
STORMS WILL AGAIN BE POSSIBLE DURING THE EVENING...ESPECIALLY
ACROSS THE SOUTHEASTERN PORTION OF THE CWA. BY 06Z FRIDAY...THE
COLD FRONT SHOULD REACH THE DULUTH AREA...AND IT SHOULD JUST ABOUT
CLEAR THE SOUTHEAST CWA BY 12Z FRIDAY. WINDS WILL SWITCH TO THE
NORTHWEST BEHIND THE FRONT.
FRIDAY...THE SHOWERS AND STORMS WILL GRADUALLY DIMINISH FROM THE
WEST. ONLY A FEW SHOWERS WILL LINGER FAR EAST INTO THE AFTERNOON.
DRIER AIR WILL PUSH IN FROM THE NORTHWEST...AS DRIER AND COOLER
AIR SPREADS INTO THE AREA FROM CANADIAN HIGH PRESSURE. HIGHS WILL
BE IN THE 50S FOR MOST OF NE MN...WITH SOME 60S IN WI.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU MAY 7 2015
HIGH PRESSURE AT THE SURFACE WILL BE BUILDING IN ACROSS SRN MANITOBA
AND WRN ONTARIO FRIDAY NIGHT AND SATURDAY...AND INTO LAKE SUPERIOR
SAT NIGHT. AS THE HIGH SHIFTS SLIGHTLY TO THE EAST THE NEXT
SIGNIFICANT LOW PRESSURE SYSTEM WILL MOVE FROM THE SRN PLAINS INTO
THE UPPER MIDWEST BY LATE SUNDAY NIGHT/MON MORNING. THE COMBINATION
OF THE SFC HIGH AND APPROACHING LOW TO THE SOUTH WILL INDUCE A
PERSISTENT E/NE WIND OFF LAKE SUPERIOR FRI NIGHT THROUGH MONDAY
NIGHT. THE APPROACHING SYSTEM WILL ONCE AGAIN DRAW UP A LARGE SUPPLY
OF MOISTURE FROM THE SOUTH AND DEPOSIT IT IN THE FORM OF WIDESPREAD
RAIN SHOWERS ACROSS THE NORTHLAND THROUGH THE DAY SUNDAY AND
CONTINUING INTO MONDAY AS THE SYSTEM WRAPS UP MOVING INTO THE GREAT
LAKES. THIS SYSTEM WILL BE FAIRLY DYNAMIC WITH A STRONG WARM FRONT
OUT AHEAD OF THE LOW...WHICH COULD BE CAPABLE OF PRODUCING SCATTERED
THUNDERSTORMS WITH THE SHOWERS DURING THE DAY SUNDAY. THE SYSTEM
THEN BEGINS TO LOOK MORE LIKE A WINTER-TYPE LOW AS AN AREA OF COLDER
AIR FILLS IN ON THE BACK SIDE...AND A TROWAL-LOOKING FEATURE
DEVELOPS TO THE EAST WITH AN AREA OF ROBUST STRATIFORM RAIN FORMING
IN THE DEFORMATION ZONE ACROSS NRN MN. THE RAIN SHOULD LINGER INTO
LATE MONDAY AND EARLY TUESDAY AS THE COLD AIR CONTINUES TO DROP IN
ACROSS THE UPPER MIDWEST BEHIND THE DEPARTING SYSTEM. THE AMT AND
DEPTH OF THE COLD AIR COULD ACTUALLY CHANGE OVER TO RAIN OR MIX WITH
SNOW AT TIMES TUESDAY MORNING. NO ACCUMULATION IS EXPECTED AT THIS
TIME. HIGH PRESSURE WILL BUILD IN BEHIND THE SYSTEM INTO THE MIDDLE
OF THE WEEK...BUT ONLY FOR A BRIEF PERIOD AS THE NEXT WEAK INVERTED
TROUGH SLIDES IN FROM THE WEST WITH ADDITIONAL CHANCES FOR LIGHT
RAIN.
TEMPERATURES WILL BE NOTICEABLY COOLER THROUGH MUCH OF THE EXTENDED
PERIOD...ESPECIALLY AROUND THE TWIN PORTS AREA WITH A PERSISTENT
E/NE WIND OFF LAKE SUPERIOR. WHILE AREAS INLAND COULD SEE UPPER 50S
AND 60S AT TIMES...LOCATIONS CLOSER TO THE LAKE WILL ONLY SEE 40S
AND LOWER 50S DURING THE DAY. THE PRESENCE OF A LAKE BREEZE WILL
MAKE IT SEEM EVEN COLDER. OVERNIGHT LOWS WILL GENERALLY BOTTOM OUT
IN THE 30S AND LOWER 40S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1232 PM CDT THU MAY 7 2015
THE WIDESPREAD MVFR CIGS ACROSS NE MINNESOTA AND NW WISCONSIN
EARLY THIS AFTERNOON WILL LIKELY CONTINUE UNTIL LATE FRIDAY
MORNING. SOUTHERLY FLOW AHEAD OF A LOW IN NW MINNESOTA SHOULD
CONTINUE TO CAUSE WIDESPREAD BKN/OVC CIGS BETWEEN 2 AND 4 KFT
AGL. THERE WILL BE PERIODS OF -SHRA AND -TSRA THROUGH THIS
EVENING. THE MAIN THREAT FOR -TSRA WILL BE LATER THIS AFTERNOON
AND THIS EVENING WHEN THE LOW AND ITS COLD FRONT MOVE THROUGH THE
REGION...FROM WEST TO EAST. NORTHWEST WINDS OF 10 TO 20 KNOTS WILL
DEVELOP IN THE WAKE OF THE COLD FRONT LATER TODAY AND TONIGHT.
THERE COULD BE BRIEF PERIODS OF IFR CIGS/VSBYS LATER THIS
AFTERNOON AND THIS EVENING DURING THE STORMS AND DUE TO MIST
FORMING IN THE WAKE OF HEAVIER SHOWERS. IFR CIGS COULD ALSO BE
POSSIBLE AT TIMES TONIGHT...BUT CONFIDENCE RELATIVELY LOW. THINK
THE NW WINDS WILL HELP LIFT THE CIGS TO KEEP CIGS PRIMARILY IN
MVFR.
THERE SHOULD BE LIFTING AND SCATTERING LATE FRIDAY MORNING AND
FRIDAY AFTERNOON. MOST TERMINALS SHOULD RETURN TO VFR BY FRIDAY
AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 69 47 58 40 / 80 80 20 0
INL 68 42 53 34 / 80 70 20 0
BRD 70 47 57 39 / 80 60 10 0
HYR 76 53 63 41 / 70 80 20 0
ASX 79 52 62 37 / 70 70 30 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...DAP
LONG TERM...BJT
AVIATION...GROCHOCINSKI
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
133 PM CDT Thu May 7 2015
.UPDATE:
Issued at 1233 PM CDT Thu May 7 2015
Updated the grids based on current trends. Convection has started
to dvlp prior to noon and should continue to expand in coverage
thru the aftn. There should be two areas of better coverage
though. One area will be across cntrl/NE MO into w cntrl IL in
assoc with ongoing convection that has dvlpd in advance of a
complex mvng out of ern KS this mrng and the other is in assoc
with a vort max mvng NE out of SW MO. This feature is fcst to be
near STL by 00Z this evng. I expect the precip coverage to expand
thru the aftn as this feature approaches the metro area. Both
areas should move NE of the CWA by early evng allowing for a break
in the activity overnight. Luckily shear is quite limited, only
approaching 20kts by this evng so severe storms are not expected.
&&
.SHORT TERM: (Today and Tonight)
Issued at 339 AM CDT Thu May 7 2015
Short-range guidance has been consistently spitting out some sunrise
surprise showers for the past few runs. The RAP might be a little
overdone as it looks like it`s trying to break pieces of the MCV
currently over Oklahoma off and spread them northeast across the
area. That being said, radar is picking up some very light echos
developing over the eastern Ozarks at this time...so the possibility
for isolated showers does seem to be increasing this morning.
Aside from any morning showers, expect most of the morning and early
afternoon to be dry. Should see highs today similar to if not a bit
warmer than Wednesday. The MCV should lift up into the area and
provide a lifting mechanism later this afternoon. Additionally,
the cold front now over western Nebraska/Kansas will drift into
western/northwestern Missouri by late this afternoon providing an
additional focusing mechanism. Think likely PoPs across central and
northeast Missouri into west central Illinois look good with chance
PoPs further to the southeast still look good for the afternoon into
early evening. PoPs for the rest of the night are less certain
though, and short-range guidance seems to be having as much trouble
as I am figuring out how to handle the situation. MOS guidance
ranges from low chance to categorical across the area. GFS and NAM
do show a weak to moderate low level jet setting up during the
evening, with a few waves of moisture convergence in the warm sector
ahead of the front. Baroclinicity is weak, but present, so I cannot
rule out scattered to possibly numerous showers and
thunderstorms...particularly closer to the front in central and
northeast Missouri.
Carney
.LONG TERM: (Friday through Wednesday)
Issued at 410 AM CDT Thu May 7 2015
Southwest flow aloft will continue to try to bring deeper moisture
back to the Mississippi Valley Friday into the weekend. It`s
difficult to really pick out a time when thunderstorms are more or
less likely for Friday through Sunday as the foci for precipitation
will likely be fast-moving shortwaves moving over the area in the
southwest flow aloft, as well as low level boundaries from
convection. Models have the synoptic front generally draped across
northern Missouri...possibly dipping down as far south as the
Missouri river at times as it is forced south by convection. Have
some flavor of 40-70% PoPs across the area for Friday through
Saturday night with the higher end PoPs closer to the synoptic
front. Guidance has the high amplitude closed wave finally opening
up and moving int the Great Plains on Sunday with the resulting
surface low moving northeast from Kansas through Iowa into the Great
Lakes Sunday night through Monday. Resulting cold front should
sweep through the forecast area late Sunday night into early Monday
morning. Cooler and drier air will bring an end to the rain chances
by most likely by Monday afternoon. Above normal temperatures will
continue ahead of the FROPA on Monday with highs mainly in the 80s
and lows in the mid 60s. Medium range guidance drops temperatures
back below normal for Tuesday and Wednesday showing highs mainly 65
to 70 and lows mainly in the upper 40s and low 50s.
Carney
&&
.AVIATION: (For the 18z TAFs through 18z Friday Afternoon)
Issued at 1233 PM CDT Thu May 7 2015
Low confidence fcst due to convective timing and coverage issues.
SHRAs/TSTMs had already begun to initiate by late mrng and should
continue to expand in coverage this aftn. Best coverage drng the
aftn should be across cntrl/NE MO into w cntrl IL. Another area of
precip is dvlpng across the ern Ozarks in response to an upper lvl
disturbance which is lifting towards the STL metro area. Any
heavier convective element that impacts a terminal will likely
cause IFR VSBYs in heavy rain. This activity should lift NE of the
TAF sites by early this evng allowing for a break for a good
portion of the night before either more precip moves in from the
west late tonight or...more likely...addtnl convection dvlps late
Friday mrng.
Specifics for KSTL:
Convection currently forming across the ern Ozarks will have to be
watched as it lifts NNE this aftn. Do not have any more than VCTS
in the TAF as I`m not confident on the coverage of storms this
aftn. Any stronger storms impacting the terminal will have the
ability to drop the VSBY to IFR. Whatever dvlps this aftn should
be past the terminal by early evng. The rest of the night appears
dry attm. More rain is expected on Friday. Existing overnight
convection may approach the terminal towards 12Z...but if that
scenario doesn`t pan out then addtnl convection should dvlp once
again like it has today. Either way...it appears there will be at
least scttrd SHRAs/TSTMs thru a good portion of tomorrow.
2%
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1256 PM CDT THU MAY 7 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 318 AM CDT THU MAY 7 2015
SHOWERS AND THUNDERSTORMS CONTINUE MAINLY ACROSS THE SOUTHEAST PART
OF THE FORECAST AREA. SURFACE ANALYSIS SHOWS A LOW PRESSURE SYSTEM
AND COLD FRONT JUST TO THE WEST OF THE FORECAST AREA AT THIS TIME.
MODELS ARE FAIRLY CONSISTENT KEEPING THE CURRENT PRECIPITATION
ACROSS MAINLY THE EASTERN PART OF THE FORECAST AREA THROUGH DAYBREAK
OR INTO THE MORNING HOURS...BUT WHEN IT MOVES OUT THERE SHOULD BE A
BREAK IN THE PRECIPITATION FOR A TIME. THE COLD FRONT TO THE WEST OF
THE FORECAST AREA THIS MORNING IS EXPECTED TO MOVE THROUGH THE AREA
DURING THE DAY. MODELS HAVE SOME DIFFERENCES ON HOW FAST IT MOVES
THROUGH. THE GFS HAS IT MOST OF THE WAY THROUGH THE FORECAST AREA BY
MID DAY WHILE THE NAM IS SLOWER TO MOVE THROUGH. THE RAP IS CLOSER
TO THE GFS AND MOVES IT THROUGH FASTER. WENT A LITTLE IN BETWEEN AND
HAVE IT IN THE EAST AND SOUTHERN PARTS OF THE FORECAST AREA MID
AFTERNOON. THE LOCATION OF THE FRONT IS IMPORTANT AS THE NEXT UPPER
LEVEL WAVE MOVES INTO THE FORECAST AREA DURING THE LATE AFTERNOON
AND INTO TONIGHT. THE UPPER WAVE MOVES IN FROM THE SOUTHWEST SO THE
PRECIPITATION SHOULD MOVE IN FROM THE SOUTH DURING THE AFTERNOON AND
SPREAD ACROSS MUCH OF THE AREA. THE BEST CHANCES WILL BE IN THE
SOUTH OR SOUTHEAST TONIGHT. WILL HAVE TO WATCH THE SOUTHEAST...THIS
IS THE AREA WITH ONGOING FLOODING AND THE AREA THE MOST LIKELY TO
HAVE PRECIPITATION TONIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 318 AM CDT THU MAY 7 2015
GUIDANCE SUGGESTS AN UPPER TROPOSPHERIC LOW WILL EXIST OVER THE
SOUTHWESTERN CONUS TO START THE LONG-TERM FORECAST PERIOD AT 12Z
FRIDAY...WITH UPPER TROPOSPHERIC RIDGING OVER THE EASTERN CONUS.
THIS UPPER TROPOSPHERIC LOW IS EXPECTED TO MOVE NORTHEAST FRIDAY
THROUGH EARLY NEXT WEEK...LIKELY CLEARING THE CENTRAL PLAINS
SATURDAY INTO SUNDAY. QUASI-ZONAL UPPER TROPOSPHERIC FLOW IS THEN
EXPECTED ACROSS THE REGION DURING THE EARLY TO MIDDLE PART OF NEXT
WEEK.
GUIDANCE SUGGESTS UPPER TROPOSPHERIC THERMAL ADVECTION AHEAD OF THE
APPROACHING LOW WILL PROMOTE PRECIPITATION PRODUCTION ACROSS OUR AREA
FRIDAY THROUGH EARLY NEXT WEEK...WITH PERHAPS A RELATIVELY DRY
PERIOD AT SOME POINT EARLY NEXT WEEK AS THE AFOREMENTIONED UPPER
TROPOSPHERIC LOW CLEARS THE REGION. THAT SAID...GUIDANCE ALSO
SUGGESTS MULTIPLE UPPER TROPOSPHERIC PERTURBATIONS...EMBEDDED WITHIN
THE DEVELOPING QUASI-ZONAL FLOW...COULD PROMOTE ADDITIONAL
PRECIPITATION CHANCES DURING THE MIDDLE TO LATE PART OF NEXT WEEK.
GIVEN ALL THIS...POPS REMAIN INTACT ACROSS THE AREA DURING MUCH OF
THE LONG-TERM FORECAST PERIOD...WITH THE HIGHEST POPS EXISTING
BETWEEN SATURDAY AFTERNOON AND SATURDAY NIGHT AS THE UPPER
TROPOSPHERIC LOW CLEARS THE AREA.
A DRIER BOUNDARY-LAYER AIR MASS...ALONG WITH MODEST UPPER
TROPOSPHERIC LAPSE RATES...SHOULD KEEP SEVERE WEATHER AT BAY FRIDAY
INTO FRIDAY NIGHT...WITH GUIDANCE SUGGESTING POTENTIAL ENERGY WILL
REMAIN AT OR BELOW 500J/KG ACROSS MUCH OF THE CWA. THAT WILL CHANGE
FOR PORTIONS OF THE REGION SATURDAY INTO SATURDAY NIGHT HOWEVER AS
BOUNDARY-LAYER MOISTURE FLUX ACROSS THE CENTRAL PLAINS...ALONG WITH
INCREASING UPPER TROPOSPHERIC LAPSE RATES WITH THE APPROACH OF THE
UPPER TROPOSPHERIC LOW...PROMOTES POTENTIAL ENERGY ON THE ORDER OF
~1500J/KG ACROSS SOUTHERN PORTIONS OF THE CWA...AND LOWER POTENTIAL
ENERGY AS ONE MOVES NORTH ACROSS THE AREA. THESE POTENTIAL ENERGY
VALUES...WORKING IN CONCERT WITH DEEP-LAYER BULK SHEAR VALUES OF
AROUND 50KTS...COULD PRESENT YET ANOTHER OPPORTUNITY FOR SEVERE
WEATHER ACROSS PORTIONS OF THE CWA SATURDAY AFTERNOON INTO SATURDAY
NIGHT...ESPECIALLY ACROSS OUR SOUTHERN COUNTIES SOUTH OF HIGHWAY 6.
GIVEN THIS...WILL CONTINUE MENTIONING SEVERE WEATHER IN THE HWO
SATURDAY INTO SATURDAY NIGHT GENERALLY SOUTH OF HIGHWAY 6. DRIER
BOUNDARY-LAYER AIR AND DECREASING UPPER TROPOSPHERIC LAPSE RATES
SHOULD THEN ALLOW FOR A DECREASING SEVERE WEATHER THREAT AS WE MOVE
INTO THE EARLY PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1254 PM CDT THU MAY 7 2015
MVFR CIGS WILL PERSIST THROUGH MUCH OF THE PERIOD WITH A FEW
SHOWERS AND THUNDERSTORMS POSSIBLE DURING THE EVENING HOURS AHEAD
OF A SLOW MOVING COLD FRONT. EXPECT TO SEE A SLIGHT SHIFT IN WINDS
WITH THIS FRONT...FROM NORTHWESTERLY TO MORE NORTHERLY TOWARDS
EARLY MORNING FRIDAY...WITH SOME IFR STRATUS POSSIBLE IN ITS WAKE.
FOR THE TIME BEING...OPTED TO KEEPS CIGS AT MVFR LEVELS FOR
FRIDAY...BUT SOME MODEL GUIDANCE IS HINTING THIS MAY BE A BIT TOO
OPTIMISTIC FOR THE MORNING HOURS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...JCB
LONG TERM...BRYANT
AVIATION...ROSSI
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1236 PM CDT THU MAY 7 2015
.UPDATE...
ISSUED AT 1231 PM CDT THU MAY 7 2015
SHOWERS CONTINUE TO DIMINISH ACROSS THE AREA AS UPPER LOW LIFTS TO
THE NORTHEAST. FOR EARLY AFTERNOON UPDATE WILL TAPER OFF
PRECIPITATION CHANCES ON THE WEST SIDE OF THE SYSTEM. HAVE ALSO
DROPPED HIGH TEMPERATURES A BIT WITH THE COOL AIRMASS MOVING IN
BEHIND THE FRONT. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 847 AM CDT THU MAY 7 2015
SHOWER ACTIVITY CONTINUES TO SLOWLY ERODE ON THE WEST
SIDE...THOUGH THIS IS OCCURRING A BIT SLOWER THAN PREVIOUS
FORECAST. THEREFORE...HAVE INCREASED POPS A BIT THROUGH MID DAY.
COLD FRONT HAS PUSHED THROUGH CENTRAL NORTH DAKOTA...AND IS SLOWLY
EXITING THE EASTERN JAMES RIVER VALLEY. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 533 AM CDT THU MAY 7 2015
SURFACE OBSERVATIONS PORTRAYING GUSTY NORTHWEST WINDS BETWEEN 25
AND 40 MPH BEHIND THE COLD FRONT. SURFACE COLD FRONT NOW MOVING
INTO JAMESTOWN AND SOUTH INTO OAKES.HAVE INCREASED WINDS CLOSER
TO THE 06Z MAV GUIDANCE THROUGH THE AFTERNOON. NEAR WIND ADVISORY
CRITERIA IN SOME SPOTS CURRENTLY...BUT WILL HOLD OFF AS UPSTREAM
WINDS IN SOUTHERN SASKATCHEWAN ARE MORE IN THE 20 TO 30 MPH RANGE.
LATEST RADAR AND WATER VAPOR IMAGERY DEPICT THE MID/UPPER LEVEL
LOW NOW CIRCULATING OVER THE SOUTHERN JAMES RIVER VALLEY. RADAR
RETURNS SLOWLY WEAKENING WEST OF BISMARCK AND THE CURRENT GRIDDED
FORECAST HAS THE POPS DIMINISHING FROM WEST TO EAST...WHICH IS ON
TRACK. BISMARCK ASOS TOTAL PRECIPITATION LAST 24HOURS HAS BEEN
0.72 INCHES.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 317 AM CDT THU MAY 7 2015
FOCUS IN THE SHORT TERM WILL BE ON EXITING SHOWERS AND THE
POTENTIAL FOR FROST THURSDAY NIGHT.
THE LATEST 00 UTC SOLUTIONS OF THE ECMWF AND GFS ARE IN GOOD
AGREEMENT ON PROGRESSING THE UPPER LEVEL SHORTWAVE AND UPPER LEVEL
LOW NORTHEAST OUT OF NORTH DAKOTA SHORTLY AFTER 18 UTC THURSDAY.
BEHIND THE UPPER LEVEL LOW THE LATEST 05 UTC RUN OF THE HRRR SHOWS
SHOWERS ACROSS CENTRAL NORTH DAKOTA BECOMING SCATTERED BY 16 UTC.
FOR THIS REASON HAVE HASTENED THE EXIT OF PRECIPITATION ACROSS
WESTERN AND CENTRAL NORTH DAKOTA. ALSO WITH OBSERVATIONS SHOWING
NOTHING IN THE WAY OF THUNDERSTORMS IN THE VICINITY OF NORTH
DAKOTA HAVE WENT AHEAD AND REMOVED ALL CHANCES FOR THUNDERSTORMS
THROUGH TODAY.
LOOKING AT THE FROST POTENTIAL FOR THURSDAY NIGHT THE BEST CHANCES
FOR FROST WILL BE WEST AND NORTH CENTRAL. MOS GUIDANCE FROM THE
GFS IS SHOWING THE LOWER 30S ACROSS THE NORTHWEST WHILE THE NAM
GUIDANCE IS SUGGESTING THE UPPER 20S. MODEL BLENDS ALSO HAVE SOME
LOW CLOUDS BUILDING BACK INTO WESTERN AND CENTRAL NORTH DAKOTA
WITH SOME MID LEVEL CLOUDS ALREADY IN PLACE. FOR NOW HAVE OPTED TO
GO WITH A MODEL BLEND FOR LOWS THURSDAY NIGHT WHICH SUGGEST A
POTENTIAL FOR FROST DEVELOPMENT ACROSS THE WEST AND PORTIONS OF
NORTH CENTRAL NORTH DAKOTA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 317 AM CDT THU MAY 7 2015
PATTERN CONTINUES TO EXHIBIT COOLER THAN NORMAL TEMPERATURES THROUGH
TUESDAY AS A POCKET OF COLDER AIR/850 TEMPERATURES HOVER BETWEEN 0C
AND -2C ACROSS WESTERN AND CENTRAL NORTH DAKOTA. A COUPLE OF
HIGHLIGHTS TO NOTE...LOWS IN THE 30S WILL LIKELY LEAD TO FROST
AND/OR FREEZE HEADLINES DURING THE LATE NIGHT/EARLY MORNING HOURS
THROUGH TUESDAY MORNING. THE SECOND HIGHLIGHT IS IN REGARDS TO
PRECIPITATION. THE MAIN THREAT STILL LOOKS TO OCCUR OVER SOUTHERN
AND EASTERN NORTH DAKOTA OVER THE WEEKEND INTO EARLY NEXT WEEK...AND
WITH THE COLDER AIR ALOFT AND COOLING AT NIGHT...EXPECT SOME SNOW
SHOWERS AT TIMES.
FRIDAY THROUGH THROUGH MONDAY NIGHT...ON FRIDAY A SURFACE HIGH WILL
SHIFT FROM SOUTH CENTRAL SASKATCHEWAN INTO MANITOBA WITH A
DRY/NORTHEAST FLOW ACROSS WESTERN AND CENTRAL NORTH DAKOTA. HIGHS
WILL BE IN THE 50S. BY FRIDAY NIGHT ATTENTION TURNS TOWARD THE NEXT
CLOSED UPPER LOW OVER THE FOUR CORNERS/SOUTHWEST CONUS AS IT BEGINS
TO EJECT EAST TO NORTHEAST INTO THE CENTRAL HIGH PLAINS SUNDAY INTO
MONDAY. SOME PHASING OCCURS BETWEEN THE NORTHERN/SOUTHERN STREAM
TROUGHS DURING THIS TIME. THE HIGHEST POPS REMAIN FOCUSED ACROSS
SOUTHERN NORTH DAKOTA SATURDAY/SATURDAY NIGHT...THEN PIVOTING INTO
SOUTH CENTRAL AND THE JAMES RIVER VALLEY SUNDAY THROUGH MONDAY. AS
MENTIONED ABOVE EXPECT SOME CHANCES FOR SNOW MIXING IN WITH THE RAIN
AT NIGHT/EARLY MORNING WITH LITTLE OR NO ACCUMULATIONS.
MONDAY NIGHT THROUGH WEDNESDAY...DRY WEATHER SLATED FOR MONDAY NIGHT
INTO WEDNESDAY. THE SUPERBLEND BEGINS TO SHOW A GRADUAL WARMING TREND
INTO THE LOWER 60S WEDNESDAY...AS 850MB TEMPERATURES WARM TO BETWEEN
+3C AND +5C. HOWEVER BOTH THE GFS AND ECMWF KEEP A CYCLONIC FLOW/SOME
TROUGHING OVER NORTH DAKOTA THROUGH THE MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1231 PM CDT THU MAY 7 2015
WIDESPREAD MVFR CIGS CONTINUE ACROSS THE AREA. CONDTIONS WILL
SLOWLY IMPROVE FROM NORTHWEST TO SOUTHEAST TO VFR THROUGH THE
AFTERNOON INTO THE EARLY EVENING. GUSTY NORTHWEST WINDS WILL
SUBSIDE LATE TODAY INTO THIS EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...MM
LONG TERM...KS
AVIATION...JJS
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1244 PM CDT THU MAY 7 2015
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...SATELLITE IMAGES AND SURFACE OBSERVATIONS INDICATE LOW
TO MID LEVEL CLOUDS ACROSS MOST OF THE CWA EARLY THIS AFTERNOON.
CEILINGS WERE NEAR 1200FT AT KT65 AND KHRL TO NEAR 2200FT AT KBKS.
VISIBILITIES WERE NEAR 4SM WITH MIST AT KPIL TO NEAR 6SM WITH HAZE
AT KMFE. EXPECT MVFR CONDITIONS TO PREVAIL THE REST OF THE
AFTERNOON INTO THE EVENING BEFORE IFR CONDITIONS DEVELOP TONIGHT
AS ABUNDANT LOW TO MID LEVEL MOISTURE UNDER THE INVERSION AT 850MB
CONTINUES TO PROVIDE LOW CEILINGS THROUGH THE PERIOD.
&&
.PREV DISCUSSION... /ISSUED 535 AM CDT THU MAY 7 2015/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...LOW MVFR CIGS ARE OCCURRING ACROSS ALL OF DEEP SOUTH
TEXAS. MUCH LIKE THE PAST SEVERAL DAYS...LOW MVFR WILL SLOWLY
RISE THROUGH THE MORNING HOURS THAT BECOMING LOW VFR THIS
AFTERNOON. SFC FEATURES HAVE NOT CHANGED MUCH WHICH WILL LEAD TO
ANOTHER BREEZY DAYS WITH GUSTS TO 25 KNOTS POSSIBLE THIS
AFTERNOON. WINDS WILL DECREASE AFTER SUNSET WITH CIGS LOWERING TO
MVFR THIS EVENING THEN PERHAPS IFR OVERNIGHT.
PREV DISCUSSION... /ISSUED 328 AM CDT THU MAY 7 2015/
SHORT TERM /NOW THROUGH FRIDAY/...H5 TROF WILL SLIDE SOUTHWARD
ACROSS CALIFORNIA AND INTO THE DESERT SOUTHWEST. MID LEVEL RIDGE
WILL BE DRAPED ACROSS THE WESTERN GULF OF MEXICO AND A S/W TROUGH
OFF THE FLORIDA COAST. PERSISTENT SOUTHEASTERLY FLOW WILL CONTINUE
WITH SFC HIGH PRESSURE ACROSS THE NORTHEASTERN GULF OF MEXICO AND
LOW PRESSURE ACROSS THE HIGH PLAINS. BREEZY CONDITIONS WILL
CONTINUE THROUGH THE SHORT TERM PERIOD WITH GUSTS TO 25-30 MPH
POSSIBLE IN THE AFTERNOON HOURS. 850-700MB TEMPERATURES WARM
THROUGH THE PERIOD SO AN INCREASE AN AFTERNOON HIGHS UP INTO THE
LOWER 90S MIDDLE/UPPER VALLEY WITH UPPER 80S IN THE LOWER VALLEY
EACH DAY.
FOR PRECIPITATION CHANCES...HAVE SLIGHT CHANCE POPS THIS MORNING FOR
ANY ISOLATED SHOWER THAT HAPPENS TO DEVELOP UNDERNEATH THE STRONG
INVERSION /MUCH LIKE THE PAST SEVERAL DAYS/. MODELS ONCE AGAIN
PROG A WEAK DISTURBANCE MOVING ACROSS THE HIGHER TERRAIN THIS
AFTERNOON AND EVENING. HRRR AND GFS DEVELOP THUNDERSTORMS OVER THE
SIERRA MADRES THIS AFTERNOON AND MOVE EAST TOWARDS THE UPPER
VALLEY. WILL MAINTAIN SLIGHT CHANCE POPS OUT WEST THIS EVENING
THEN DECREASE OVERNIGHT AS CIN INCREASES RAPIDLY.
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...THE APPROACH AND
PASSAGE OF A 500 MB TROUGH THROUGH THE TEXAS BIG BEND WILL ONCE
AGAIN INITIATE THUNDERSTORMS OVER THE NEIGHBORING HIGH TERRAIN OF
MEXICO...AND SOME OF THIS ACTIVITY MAY AFFECT THE BRO CWFA...
ESPECIALLY THE WESTERN THIRD AND NORTHERN HALF OF THE REGION.
STORM PREDICTION CENTER HAS A MARGINAL TO ENHANCED RISK OF SEVERE
WEATHER FOR MUCH OF TEXAS NORTH OF THE RIO GRANDE VALLEY AND DEEP
SOUTH TEXAS...SO SUCCESSIVE SHIFTS WILL HAVE TO MONITOR FOR THE
POSSIBILITY THAT SOME OF THIS STRONG TO SEVERE THUNDERSTORM
ACTIVITY MAY SNEAK INTO THE BRO CWFA FRIDAY NIGHT. AFTERWARDS...DRY
WEATHER WILL PREVAIL UNTIL ANOTHER POSSIBLE ROUND OF THUNDERSTORMS
OUT WEST SUNDAY NIGHT. A GREATLY ENHANCED OPPORTUNITY FOR RAINFALL
IS ANTICIPATED MONDAY THROUGH WEDNESDAY DUE TO THE INTRUSION AND
STALLING OF A WEAK COLD FRONT...A SOUTHWEST-TO-NORTHEAST 500 MB
FLOW OVERHEAD...AND THE FORMATION AND PERSISTENCE OF A SURFACE
TROUGH OF LOW PRESSURE WITHIN THE BRO CWFA. WITH DEEP TROPICAL
MOISTURE EXPECTED TO ALSO BE IN PLACE...WITH PRECIPITABLE WATER
VALUES AROUND 2 INCHES...THE POTENTIAL FOR LOCALLY HEAVY AND
FLOODING RAINFALL MAY EXIST MONDAY THROUGH WEDNESDAY. HOWEVER
.HAVE NOT INCLUDED THIS IN THE UPCOMING FORECAST AND WILL KEEP
AN EYE ON THE POTENTIAL FOR THIS HEAVY/FLOODING RAINFALL THROUGH
THE NEXT SEVERAL DAYS. NO MAJOR SURPRISES FOR THE TEMPERATURES...
NEAR TO SLIGHTLY ABOVE NORMAL THROUGHOUT THE ENTIRE LONG TERM
FORECAST PERIOD.
MARINE...NOW THROUGH FRIDAY...SEAS WERE NEAR 5 FEET WITH SOUTHEAST
WINDS NEAR 16 KNOTS AT BUOY020 THIS MORNING. MODERATE TO STRONG
SOUTHEAST WINDS WILL PREVAIL ACROSS THE COASTAL WATERS TODAY AS
THE PRESSURE GRADIENT REMAINS STRONG ACROSS THE WESTERN GULF OF
MEXICO. WILL HAVE SCEC ACROSS ALL LOWER TEXAS COASTAL WATERS TODAY
AND GULF WATERS TONIGHT. FOR FRIDAY SCEC WILL BE NEEDED ACROSS ALL
LOWER TEXAS COASTAL WATERS ONCE AGAIN.
FRIDAY NIGHT THROUGH WEDNESDAY...SURFACE HIGH PRESSURE CENTERED
JUST SOUTH OF THE FLORIDA PENINSULA WILL INTERACT WITH PERSISTENT
LOW PRESSURE OVER THE CENTRAL PLAINS FROM FRIDAY NIGHT THROUGH
THE WEEKEND...PRODUCING SMALL CRAFT ADVISORY WINDS/SEAS ALONG THE
LOWER TEXAS COAST THROUGH THIS PERIOD. ALTHOUGH HIGH PRESSURE WILL
BECOME MORE IN CONTROL OVER THE WESTERN GULF OF MEXICO AFTERWARDS
.ROUGH SWELLS FROM THE EAST-SOUTHEAST TO SOUTHEAST WILL CONTINUE
THE CHANCE FOR SMALL CRAFT ADVISORY MONDAY THROUGH WEDNESDAY...
ESPECIALLY FOR THE FAR OFFSHORE GULF OF MEXICO WATERS.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
61/67/BIRCHFIELD
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1231 PM CDT THU MAY 7 2015
.UPDATE...
WILL UPDATE TO INCREASE AFTN POPS NERN ZONES WHERE A CONVECTIVE
COMPLEX WILL CONTINUE TO MOVE SLOWLY ACROSS. APPEARS COMPLEX
ITSELF MAY TAKE MORE OF AN EWD TURN FEEDING INTO INCREASINGLY
MOIST AND UNSTABLE AIR ADVECTING INTO THAT AREA FROM THE SOUTH.
UNCERTAINTY REIGNS FURTHER TO WEST WITH POTENTIAL FOR
REDEVELOPMENT OF STORMS LOOKING MORE UNLIKELY WITH SUBSIDENCE ON
IN THE WAKE OF THE THUNDER COMPLEX AND ASSOCIATED SHORT WAVE
TROUGH. HEAVY RAIN TO REMAIN A THREAT THROUGH THE AFTN...BUT
SEVERE REMAINS A POSSIBILITY AS STORMS BUILD EWD ACROSS THE
ROLLING PLAINS.
&&
.AVIATION...
UPPER TROUGH TO CONTINUE TO MOVE SLOWLY TO THE ENE ACROSS THE AREA
WITH TS COMPLEX GRADUALLY SHIFTING THAT DIRECTION AS WELL. THIS
WILL TAKE TS AWAY FROM KLBB AND KPVW WITHIN THE FIRST HOUR OR TWO
OF THE TAF VALID TIME. COMPLEX LIKELY TO AFFECT KCDS THRU MIDDLE
AFTN. REDEVELOPMENT OF TS FURTHER WEST THIS AFTN POSSIBLE BUT NOT
LOOKING AS LIKELY WITH CLOSE PROXIMITY TO DOWNWARD MOTION AROUND
EDGE OF THE CONVECTIVE COMPLEX. FINALLY...IFR CIGS LIKELY TO
RETURN TO ALL TERMINALS OVERNIGHT TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 1017 AM CDT THU MAY 7 2015/
UPDATE...
QUICK UPDATE TO INCREASE POPS FOR THE REMAINDER OF THE MORNING. AN
UPPER LEVEL SHORT WAVE TROUGH LIFTING NEWD ACROSS SERN NM ACTING
ON ELEVATED INSTABILITY HELPING KICK OFF SCATTERED TO NUMEROUS
THUNDERSTORMS. THIS TROUGH IS EXPECTED TO EXIT THE REGION BY MID
AFTERNOON AND ITS EGRESS COULD HAVE A NEGATIVE EFFECT ON
CONVECTIVE INITIATION LATER THIS AFTERNOON GIVEN EXPECTATION OF
SOME DOWNWARD MOTION IN ITS WAKE AND THE RELEASE OF POTENTIAL
ENERGY THIS MORNING WITH THIS ROUND OF STORMS. WILL KEEP POST-18Z
POPS ALONE ATTM WITH THE WEST TO EAST GRADIENT LOOKING FINE AS
SOME SHOWERS AND STORMS LIKELY TO LINGER PAST 18Z. NO OTHER
CHANGES MADE ATTM.
PREV DISCUSSION... /ISSUED 351 AM CDT THU MAY 7 2015/
SHORT TERM...
JUST AS WE SAW LAST NIGHT...STORMS MOVED OUT OF THE AREA OR WEAKENED
JUST AFTER MIDNIGHT LOCAL TIME AND THE DRYLINE CONTINUES TO SLOSH
BACK TO THE WEST. ONE DIFFERENCE IS THAT THERE IS A SUBTLE
SHORTWAVE OVER SOUTHEAST NEW MEXICO THAT IS TRYING TO GENERATE SOME
SHOWERS AS IT APPROACHES THE REGION. THIS SHORTWAVE MAY COMPLICATE
MATTERS FOR THIS AFTERNOON IF PRECIPITATION CAN DEVELOP AND BECOME
MORE EXPANSIVE ACROSS THE FORECAST AREA. THE RAP AND HRRR AND TO
SOME EXTENT THE NAM ARE TRYING TO DEVELOP AN AREA OF PRECIPITATION
ACROSS THE SOUTHWESTERN SOUTH PLAINS AND SOUTHEASTERN NEW MEXICO
THAT SPREADS NORTHEAST BEFORE SUNRISE. AMPLE LOW LEVEL MOISTURE
WILL BE IN PLACE TO THE EAST OF THE DRYLINE AS INDICATED BY LOW
CLOUDS AND PATCHY FOG ONCE AGAIN DEVELOPING ACROSS THE ROLLING
PLAINS AND STARTING TO SPREAD OVER THE CAPROCK. PULLED POPS BACK TO
THE WEST FOR THIS MORNING BUT KEPT THEM BARELY IN THE SLIGHT CHANCE
RANGE.
STORM CHANCES FOR THIS AFTERNOON WILL ONCE AGAIN DEPEND ON WHERE THE
DRYLINE MIXES TO AND IF ANY OTHER WEAK SHORTWAVES WILL MOVE ACROSS
THE AREA TO PROVIDE SOME WEAK LIFT TO INITIATE STORMS. FORECAST
SOUNDINGS STILL SHOW A BIT OF A WEAK CAP OVER THE AREA THIS MORNING
BUT THIS COULD EASILY BE OVERCOME BY DAYTIME HEATING. MLCAPE VALUES
WILL ONCE AGAIN CLIMB INTO THE 2000-3000 J/KG SO THERE WILL BE
PLENTY OF ENERGY FOR STORMS TO ACCESS. WIND PROFILES SHOW A BIT OF
A WEAKNESS BETWEEN 850 AND 700 HPA WHICH MAY IMPACT STORM MORPHOLOGY
BUT AMOUNT OF INSTABILITY AND DECENT VENTILATION ALOFT POINTS
TOWARDS THE POSSIBILITY OF SUPERCELLS WITH LARGE HAIL THE PREDOMINANT
THREAT. HOWEVER...RADAR LOOP SHOWS THAT THERE IS A POSSIBLE OUTFLOW
BOUNDARY FROM THE STORMS OVER OKLAHOMA/NORTH TEXAS THAT IS PUSHING
WEST. ADD IN BOUNDARIES LEFT OVER FROM ANY STORMS THAT MAY OR MAY
NOT DEVELOP THIS MORNING AND THERE COULD BE SOME LOCALIZED THREAT
FOR TORNADO DEVELOPMENT ALONG THESE BOUNDARIES. UNFORTUNATELY IT
IS TOO HARD TO TELL RIGHT NOW IF THERE WILL BE ANY ONE AREA OVER
ANOTHER THAT HAS A GREATER THREAT FOR TORNADOES.
TEMPERATURES WILL BE FAIRLY CLOSE TO WHAT WE SAW YESTERDAY FOR BOTH
MIN AND MAX TEMPS. AS MENTIONED EARLIER...DID INCREASE POPS THIS
MORNING AND ALSO INCREASED POPS ACROSS THE ROLLING PLAINS FOR THIS
AFTERNOON. PUT MENTION OF SEVERE IN FOR THE EASTERN TWO THIRDS OF
THE FORECAST AREA FOR THIS AFTERNOON AND EARLY EVENING BUT TAPERED
POPS OFF AFTER MIDNIGHT A BIT FOLLOWING THE DIURNAL CYCLE WE HAVE
SEEN THE LAST SEVERAL DAYS.
JORDAN
LONG TERM...
LITTLE CHANGE TO THE EXTENDED FORECAST WITH THE PRIMARY FOCUS ON THE
ACTIVE EARLY MAY WEATHER THAT WILL PERSIST IN THE REGION INTO
SATURDAY.
THE UPPER LOW CURRENTLY DIGGING SOUTHWARD ACROSS THE WESTERN STATES
WILL BE CENTERED OVER SOUTHERN CA/NV TO KICK OF THE EXTENDED FRIDAY.
THERE IS GOOD AGREEMENT THAT THE LOW WILL MOVE STEADILY EASTWARD TO
NEAR THE FOUR CORNERS AROUND MIDDAY SATURDAY BEFORE EMERGING OVER
THE CENTRAL HIGH PLAINS ON SUNDAY. THIS TRACK WILL KEEP WEST TEXAS
UNDER STRENGTHENING SOUTHWESTERLY FLOW ALOFT WHILE RICH MOISTURE
ALREADY ENCOMPASSING MUCH OF THE LONE STAR STATE DOES NOT GO
ANYWHERE. VERY STEEP MID-LEVEL LAPSES ATOP THE RICH AND MOIST
BOUNDARY LAYER EAST OF THE DRYLINE WILL RESULT IN STRONG INSTABILITY
EVERY DAY...THOUGH ANY EARLY DAY CONVECTION AND CLOUD COVER WILL
DICTATE WHERE THE MOST VOLATILE AIR WILL RESIDE ON ANY PARTICULAR
AFTERNOON/EVENING. THE ABOVE FACTORS WILL WILL SET THE STAGE FOR
ROBUST MOIST CONVECTION ALONG AND EAST OF THE DRYLINE THE NEXT FEW
DAYS...WITH ALL FORMS OF SEVERE WEATHER /VERY LARGE HAIL...DAMAGING
WINDS AND ISOLATED TORNADOES/ POSSIBLE IN ADDITION TO LOCALLY HEAVY
RAIN.
CONVECTION COULD START FAIRLY EARLY ON FRIDAY AS ANOTHER SUBTLE
SHORTWAVE TROUGH IS PROGGED TO ROTATE AROUND THE UPPER LOW AND
APPROACH THE SOUTH PLAINS REGION BY MIDDAY OR SO. RECENT NWP SUGGEST
THE DRYLINE WILL BE POSITIONED SOMEWHERE NEAR THE EDGE OF THE
CAPROCK TOMORROW AFTERNOON...SO THE HIGHEST SEVERE WEATHER
PROBABILITIES WILL BE ALONG AND EAST OF THIS LINE FRIDAY
AFTERNOON/EVENING...THOUGH LOCATIONS FURTHER WEST COULD SEE
CONVECTION EARLY IN THE DAY. THE DRYLINE SHOULD QUICKLY RETREAT
FRIDAY NIGHT AS THE FLOW BACKS IN RESPONSE TO THE APPROACHING UPPER
LOW. IT APPEARS THE MOISTURE COULD MAKE IT ALL THE WAY BACK TO
THE TX/NM LINE FOR A SHORT TIME EARLY SATURDAY BEFORE
STRENGTHENING LOW-LEVEL SOUTHWESTERLY FLOW SHUNTS THE MOISTURE
BACK EASTWARD. ALTHOUGH NWP SIGNALS ARE MIXED...WE WOULD EXPECT
CONVECTION TO ERUPT ALONG THE DRYLINE EARLY SATURDAY AS THE
STRONGEST UPPER LIFT GRAZES THE AREA. THE DRYLINE AND EARLY DAY
CONVECTION SHOULD THEN RACE EASTWARD AS THE DRIER SOUTHWEST WINDS
SPREAD FROM WEST TO EAST ACROSS THE FA. THE DRYLINE MAY MAKE IT
ALL THE WAY TO OR EVEN SLIGHTLY EAST OF THE CWA BY SATURDAY
EVENING...THOUGH WE HAVE MAINTAINED SLIM POPS ACROSS THE FAR
EASTERN ZONES GIVEN THE UNCERTAINTY. WEST OF THE DRYLINE BREEZY TO
LOW-END WINDY CONDITION WILL ENVELOP THE CAPROCK SATURDAY
AFTERNOON WHILE TEMPERATURES PEAK NEAR EARLY MAY AVERAGES.
THE DRY WESTERLY FLOW WILL PERSIST OVER MUCH OF THE AREA SUNDAY WITH
MODEST COOLING AS THE UPPER TROUGH AXIS APPROACHES FROM THE WEST.
THE ONE EXCEPTION COULD BE THE FAR SOUTHEAST ZONES AROUND ASPERMONT
WHERE THE LOW-LEVEL MOISTURE MAY LINGER NEARBY AND PROVIDE AT LEAST
A LOW RISK OF A STORM.
A COLD FRONT WILL FOLLOW THE TROUGH PASSAGE EARLY MONDAY PROVIDING
BELOW AVERAGE TEMPERATURES AND DRY CONDITIONS TO BEGIN NEXT WEEK.
MOISTURE WILL GRADUALLY RETURN THEREAFTER AND WE COULD SEE THE UPPER
RIDGE EARLY IN THE WEEK BEGIN TO BREAKDOWN AND PROVIDE A RETURN OF
LOW THUNDER CHANCES TO THE FORECAST TOWARD MIDWEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 78 49 80 48 / 40 20 10 20
TULIA 79 54 81 54 / 70 20 30 40
PLAINVIEW 79 55 81 54 / 70 30 30 40
LEVELLAND 82 56 83 56 / 50 30 20 50
LUBBOCK 80 58 84 58 / 50 30 30 40
DENVER CITY 82 54 83 53 / 40 20 20 50
BROWNFIELD 83 56 85 57 / 50 30 30 50
CHILDRESS 82 61 84 64 / 70 40 50 40
SPUR 81 57 84 63 / 50 40 50 40
ASPERMONT 84 61 86 66 / 50 40 50 40
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
324 PM CDT THU MAY 7 2015
.TONIGHT...FORECAST CONFIDENCE MEDIUM.
SHOWERS AND ISOLATED THUNDERSTORMS DEVELOPED ALONG THE WI/IA BORDER
WITH SOME WEAK SHORTWAVE ENERGY THIS MORNING AND ARE SLOWLY TRACKING
EAST INTO SOUTH CENTRAL WI THIS AFTERNOON. THEY ARE WEAK SINCE THEY
ARE ENCOUNTERING A WELL-MIXED... DRY AND CAPPED ENVIRONMENT.
THE NEXT CHALLENGE IS EVENING AND OVERNIGHT PRECIP CHANCES. THE
MAJORITY OF MODELS ARE SHOWING A DRY FORECAST FOR SOUTHERN WI THIS
EVENING AS SOON AS THE ONGOING SHOWERS DISSIPATE. THERE IS AN AREA
OF SHOWERS AND THUNDERSTORMS DEVELOPING ALONG ANOTHER SHORTWAVE OVER
NORTHEAST MO THIS AFTERNOON THAT SHOULD TRACK EAST OR NORTHEAST
THROUGH THE EVENING. THE HRRR MODEL IS THE ONLY MODEL THAT IS
CONSISTENTLY DEVELOPING A LARGE PRECIP SHIELD WITH THAT CONVECTION
AND BRINGING IT INTO SOUTHERN WI. THEREFORE... WENT WITH JUST SLIGHT
CHANCES FOR SHOWERS AND THUNDERSTORMS THIS EVENING.
THE OVERNIGHT WEATHER SHOULD BE QUIET ACROSS SOUTHERN WI. THERE IS
NOT MUCH SUPPORT FOR SHOWER/TSTORM DEVELOPMENT. KEPT SCHC POPS...BUT
THIS MAY BE ABLE TO BE REMOVED.
FRIDAY... FORECAST CONFIDENCE MEDIUM.
A WEAK COLD FRONT WILL SLIDE SOUTHEAST THROUGH SOUTHERN WI ON
FRIDAY. THIS MAY TRIGGER SOME THUNDERSTORMS AS IT REACHES SOUTHEAST
WI FRIDAY AFTERNOON. KEPT THE LIKELY POPS FOR THIS AREA. MODEL
SOUNDINGS SHOW A GOOD AMOUNT OF CAPE BUT WEAK SHEAR... SO NOT
EXPECTING SEVERE STORMS.
TEMPERATURES WILL BE WARM ONCE AGAIN AHEAD OF THIS FRONT ON FRIDAY.
EXPECT A LAKE BREEZE TO DEVELOP IN THE EARLY AFTERNOON ONCE AGAIN.
.FRIDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM.
A SURFACE COLD FRONT WILL BE WORKING THROUGH THE AREA DURING THE
EVENING...BUT THE MODELS ARE ALL OVER THE PLACE WITH
TIMING. THE GFS HAS IT EXITING KENOSHA RIGHT AROUND 00Z SAT...
WHILE THE ECMWF IS STILL BACK OVER MADISON OR JUST NW OF MADISON.
THE NAM IS IN BETWEEN. ALL THE MODELS SHOW A WEAK MID LEVEL WAVE
ROLLING UP HERE IN THE DEEP SOUTHWEST FLOW AT THAT TIME. GIVEN
THAT THE FLOW IS SOUTHWEST...WILL DISCARD THE FAST GFS AS A FASTER
SOLUTION ISN/T TYPICAL WITHOUT ENCOURAGEMENT ALOFT. WE BUILD SOME
CAPE IN THE AFTERNOON...SO WILL KEEP THE LIKELY POPS ACROSS THE
SOUTHEAST WITH FROPA AND THE MID LEVEL WAVE COMBO.
NORTH TO NORTHEAST WINDS IN THE WAKE OF THE FRONT WILL COOL DOWN
THE LAKE SHORE AREAS SIGNIFICANTLY BY MORNING.
.SATURDAY AND SATURDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM.
THE COLD FRONT WILL BE SOUTH OF US BY SUNRISE SATURDAY MORNING
WITH A COOLER AND DRIER NORTHEAST TO EAST FLOW OVER ALL OF
SOUTHERN WISCONSIN. IF YOU/RE HEADED OVER TOWARD LAKE
MICHIGAN...IT WILL BE CHILLY. THE UPPER FLOW REMAINS SOUTHWEST ON
SATURDAY AND THE MODELS STILL SHOW SOME SHORT WAVE ENERGY
POTENTIALLY ROLLING UP HERE. HOWEVER...THE COLUMN WILL BE PRETTY
DRY AND THE BEST LOW LEVEL FORCING WILL BE WELL SOUTH. HOWEVER...
WILL HANG ONTO A SMALL CHANCE OVER THE FAR SOUTH IN CASE ANY
SHOWERS SNEAK FARTHER NORTH.
RAIN CHANCES WILL INCREASE SATURDAY NIGHT AS A STRONG UPPER LOW
BEGINS TO DEVELOP OVER THE CENTRAL PLAINS AND WE GET INTO A
STRENGTHENING SOUTHERLY FLOW...AT LEAST ABOVE THE BOUNDARY LAYER.
THE 850MB WARM FRONT SHOULD GET INTO SOUTHERN WISCONSIN AND THIS
COULD A FOCUS FOR ELEVATED SHOWERS AND POSSIBLE THUNDERSTORMS.
THE WARM AIR ADVECTION IS MODEST.
.SUNDAY INTO MONDAY...FORECAST CONFIDENCE IS MEDIUM.
THE STRONG...CLOSED UPPER LOW IS PROGGED TO BE OVER WRN NEB
SUNDAY MORNING AND MOVING VERY SLOWLY TO SOUTHERN MN BY MONDAY
EVENING...BECOMING AN OPEN TROF BY THAT TIME. THIS PUTS US IN A
PERSISTENT SOUTHERLY FLOW WITH THE USUAL TIMING ISSUES RELATED TO
SHORT WAVE IMPULSES ROLLING NORTH AHEAD OF THE UPPER LOW. THE SFC
COLD FRONT LOOKS LIKE IT MAY STAY SOUTH OF WISCONSIN THROUGH THE
DAY ON SUNDAY...BUT THE 850MB BOUNDARY WILL BE WELL NORTH. GIVEN
THE STRENGTHENING UPPER LEVEL DIVERGENCE AND LOW LEVEL JET...IT
LOOKS LIKE SHOWERS AND STORMS WILL BE LIKELY SUNDAY. THE CHANCES
INCREASE SUNDAY NIGHT AS THE SURFACE FRONT LIFTS NORTH. CAN/T RULE
OUT SEVERE WEATHER...BUT THE BETTER CAPE STAYS TO OUR SOUTH
THROUGH SUNDAY NIGHT.
MONDAY IS LOOKING INTERESTING AS THE STACKED LOW MOVES NORTHEAST
INTO THE SOUTHERN MN VCNTY. TIMING IS KEY HERE...AS ALWAYS. THERE
IS A SMALL WINDOW OF OPPORTUNITY FOR STRONG/SEVERE WEATHER...BUT
IT LOOKS LIMITED TO MAINLY THE EASTERN PORTION OF THE FORECAST
AREA. A NARROW BAND OF HIGHER CAPE AND SHEAR SHOULD DEVELOP AHEAD
OF AN ADVANCING COLD FRONT. THE MID LEVEL WESTERLIES AND LOW LEVEL
SOUTHERLY JET WILL ALSO INCREASE CONSIDERABLY INTO SOUTHERN
WISCONSIN. BUT THIS COULD ALL PUSH EAST BEFORE THE FAVORABLE
DIURNAL MAX...OR STAY FOCUSED JUST TO OUR SOUTH...KEEPING US ON
THE MORE STABLE SIDE OF THINGS. LOTS OF UNCERTAINTY...BUT THERE IS
LOTS OF ENERGY MOVING THROUGH THE UPPER MIDWEST.
.TUESDAY AND WEDNESDAY...FORECAST CONFIDENCE IS MEDIUM.
HIGH PRESSURE WILL BUILD IN FOR MID WEEK. WE MIGHT SEE SOME
SHOWERS ON TUESDAY...BUT THAT CHANCE IS PRETTY SMALL AT THIS
POINT. THE RIDGE WILL BE OVERHEAD ON WEDNESDAY...SO QUIET AND
COOL.
&&
.AVIATION/00Z TAFS/...
UNCERTAINTY WITH THUNDERSTORM CHANCES FOR THE NEXT 30 HOURS... BUT
IT LOOKS LIKE SOUTHEAST WI WILL HAVE THE BEST CHANCE FRIDAY
AFTERNOON ALONG A COLD FRONT TRACKING SOUTHEAST THROUGH THE STATE.
THERE ARE SOME INDICATIONS FOR FOG AND LOW CLOUDS TO DEVELOP OVER
PORTIONS OF CENTRAL WI DUE TO A WEAK PRESSURE GRADIENT WITH A
SURFACE TROUGH AND INVERSION EARLY FRIDAY MORNING. LOWEST CEILINGS
SHOULD BE NORTHWEST OF MADISON... BUT MVFR VSBY IS POSSIBLE ACROSS
ALL OF SOUTHERN WI.
&&
.MARINE...
MARINE FOG MOSTLY DISSIPATED OVER SOUTHERN LAKE MICHIGAN TODAY BUT
IT COULD REDEVELOP TONIGHT WITH WARM AND MOIST AIR LINGERING OVER
THE AREA.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TONIGHT/FRIDAY AND AVIATION/MARINE...MRC
FRIDAY NIGHT THROUGH THURSDAY...DAVIS
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1201 PM MDT THU MAY 7 2015
.UPDATE...
ISSUED AT 1159 AM MDT THU MAY 7 2015
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 526 AM MDT THU MAY 7 2015
WYDOT WEBCAMS CONTINUE TO INDICATE PATCHY FOG OVER THE INTERSTATE 80
SUMMIT AND ADJACENT FOOTHILLS EARLY THIS AM. PERSISTENT LLVL UPSLOPE
AND ABUNDANT BOUNDARY LAYER MOISTURE SHOULD REMAIN IN PLACE THROUGH
MID MORNING...SO EXPECT THIS TO CONTINUE FOR A FEW MORE HOURS. HAVE
NOT SEEN ANYTHING PARTICULARLY DENSE...SO DO NOT SEE ANY NEED FOR A
DENSE FOG ADVISORY AT THIS TIME. THE HRRR SHOWS LOCALLY REDUCED VSBY
TO AROUND ONE QUARTER OF A MILE THROUGH 15Z...THEN DISSIPATING. THIS
SEEMS TO MAKE SENSE WITH MOISTURE PROFILES ON BUFKIT SOUNDINGS. KCYS
RADAR LOOP SHOWS SHOWER ACTIVITY WINDING DOWN OVER FAR SOUTHEAST WY
INTO THE SOUTHERN NE PANHANDLE. THE NAM SHOWS WINDS SHIFTING TO THE
EAST/NORTHEAST AFTER 18Z AS A MID LEVEL DISTURBANCE MOVES OUT OF CO
AROUND THE SAME TIME. THIS FRAGMENTED WAVE WAS OBSERVED AT 12Z PER
RECENT WATER VAPOR IMAGERY. QPF SIGNALS INCREASE DRAMATICALLY DURING
THE AFTERNOON WITH THE RETURN OF EXCELLENT UPSLOPE...SO RAIN COULD
VERY WELL BECOME WIDESPREAD AGAIN LATER TODAY FROM THE HIGH COUNTRY
EASTWARD INTO CHEYENNE. PWAT VALUES REMAIN RESPECTABLE AROUND 0.5 TO
0.6 INCH...SO FELT COMFORTABLE BRINGING LIKELY POPS BACK INTO THE
PICTURE DURING THE LATE AFTN/EARLY EVE. THE NAM AND GFS BOTH SHOW A
RIBBON OF 500 J/KG SBCAPES ALONG THE I80 CORRIDOR IN OUR CWA...SO AT
LEAST A FEW LIGHTNING STRIKES ARE POSSIBLE. LIMITING FACTOR FOR ANY
AVAILABLE INSTABILITY WILL BE COOLER TEMPERATURES WITH UPSLOPE AND
RESULTING CLOUD COVER. THUNDERSTORMS COULD PRODUCE HAIL IN THIS TYPE
OF ENVIRONMENT IF THE MODELS VERIFY.
THINGS START TO GET INTERESTING ON FRIDAY AS A VIGOROUS LATE SEASON
WINTER STORM BEGINS TO TAKE SHAPE. WE ARE INDEED DEALING WITH A VERY
CHALLENGING FORECAST WITH RESPECT TO SNOW LEVELS AND RESULTING SNOW
AMOUNTS...AS WELL AS IMPACTS TO TRAVEL FOR MOTHERS DAY. GFS/NAM/ECM
ARE ALL IN EXCELLENT AGREEMENT WITH A VIGOROUS CLOSED LOW OVER THE
GREAT BASIN AT 12Z FRI. THIS FEATURE SLOWLY MEANDERS INTO THE FOUR
CORNERS REGION BY 06Z SAT WITH SURFACE CYCLOGENESIS RAMPING UP OVER
SOUTHEAST CO. ALL OF THE MODELS SHOW THIS SYSTEM LIFTING NORTHEAST
ON SAT NIGHT AND SUN WITH THE ASSOCIATED SUB-1000 MILLIBAR SURFACE
LOW SHIFTING INTO NORTHWEST KS. THIS TRACK ALLOWS MUCH COOLER AIR TO
SPILL INTO OUR HIGHER ELEVATION AREAS AS EARLY AS FRI NIGHT...WITH
H7 TEMPS FALLING TO -2C BY 12Z SAT. NAM WBZ HEIGHTS FALL TO AROUND
8000 FEET OR SO BY 09Z...AND FORECAST SOUNDINGS OVER THE SUMMIT ARE
FULLY SUPPORTIVE OF SNOW WHICH COULD BE HEAVY GIVEN A LAYER OF DEEP
SATURATION. A FEW PIECES OF ENERGY ROUNDING THE LOW WILL SUPPORT AN
INCREASE IN PCPN DURING THIS TIME...SO DO EXPECT THIS TO BE THE VERY
BEGINNING OF A POTENTIALLY SIGNIFICANT WINTER STORM EVENT. SLIGHTLY
NEGATIVE EPV VALUES SUGGEST ENOUGH INSTABILITY FOR A FEW CONVECTIVE
ELEMENTS AS WELL...FURTHER REINFORCING THE LIKELIHOOD OF SNOW.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 526 AM MDT THU MAY 7 2015
VERY CONCERNED THAT TRAVEL CONDITIONS MAY QUICKLY DETERIORATE BY SAT
MORNING...EVEN THOUGH THE MAIN SNOWFALL EVENT IS NOT EXPECTED UNTIL
LATER IN THE DAY ON SAT. THIS WOULD MAINLY BE OVER THE I80 SUMMIT...
BUT THIS AREA HAS BEEN A PROBLEM RECENTLY WITH VERY SIMILAR SYNOPTIC
SETUPS. WITH EARLY IMPACTS AND LIKELIHOOD OF MAJOR ACCUMULATIONS ON
SAT...WE DECIDED TO GO WITH A WINTER STORM WATCH FOR ALL OF OUR MTN
ZONES BEGINNING AT 06Z SAT. CONCERNING THE LATER EVOLUTION OF THIS
EVENT...NOTABLE COLD ADVECTION ALOFT APPEARS LIKELY ON SAT WITH H7
TEMPS FALLING TO BETWEEN -5 AND -10 DEG C ACROSS THE ENTIRE CWA BY
12Z SUN. THIS ULTIMATELY ALLOWS SNOW LEVELS TO FALL TO 5000 FEET OR
LOWER DURING THE COURSE OF THE EVENT. THE TRICKY PART WILL BE TIMING
WHEN THIS OCCURS FROM W TO E. ESPECIALLY CONCERNED ABOUT CHEYENNE AS
THE EUROPEAN SHOWS A DISTINCT COLD AIR DAMMING SIGNATURE DRAPED OVER
THE CO FRONT RANGE. THAT WAS OUR ACHILLES HEEL WITH THE LAST CLOSED
LOW WE DEALT WITH...AND IT KEPT WINDS NORTHERLY AT KCYS WITH COLDER
TEMPERATURES THAN MODELS PROGGED. THIS HAS BEEN THE ONLY MODEL TO
SHOW THIS SO FAR...BUT CAUTIOUSLY TRENDED LOWER ON TEMPS. THIS COULD
CAUSE SNOWFALL AMOUNTS TO BE SIGNIFICANTLY HIGHER AS THE HEAVIER
PCPN COULD VERY WELL BEGIN AS SNOW. WILL MAINTAIN A 6-10 INCH FCST
LOCALLY...BUT THIS MAY NEED TO BE REVISED. LATER SHIFTS WILL MOST
LIKELY NEED TO EXPAND THE WATCH EASTWARD INTO THE PLAINS. SHOULD
ALSO NOTE THAT GFS/SREF/NAM SOUNDINGS ALL SHOW A SUB-ZERO THERMAL
PROFILE AT LUSK ALL DAY ON SAT...SO COULD SEE SOME LOCALLY HIGHER
AMOUNTS IN THE HIGHER TERRAIN OUT THERE.
QPF SIGNALS FROM ALL MODELS ARE SCARY TO SAY THE LEAST. BUT ALAS...
THEY ARE BELIEVABLE WITH IMPRESSIVE MOISTURE (0.5 INCH PWATS FOR A
WINTER EVENT) COMBINED WITH EXCELLENT DYNAMIC SUPPORT BENEATH VERY
DIFLUENT FLOW AND A COUPLED UPPER JET. ALSO SEEING SOME INSTABILITY
IN THE MIX TOO WHICH WILL LIKELY LEAD TO MESOSCALE BANDING. NAM IS
STILL THE OUTLIER WITH THE HEAVIER PCPN DISPLACED WELL TO THE EAST
OF OUR CWA. GFS/ECMWF HAVE BEEN VERY CONSISTENT WITH WIDESPREAD 2-4
INCH LIQUID AMOUNTS...ESPECIALLY ALONG/EAST OF THE LARAMIE RANGE
WITH SIGNIFICANT UPSLOPE EXPECTED. THE NEW SREF IS TAGGING ALONG AS
WELL WITH HIGHER-END AMOUNTS. THAT SAID...CONFIDENCE IS VERY HIGH
THAT WE WILL SEE A SIGNIFICANT PRECIPITATION EVENT. WITH FORECAST
SOUNDINGS AS COLD AS THEY ARE...A FAIR AMOUNT OF THIS WILL PROBABLY
FALL AS SNOW. COULD SEE SEVERAL FEET IN THE MOUNTAINS. IT IS NOT
OUTSIDE OF THE REALM OF POSSIBILITY TO SEE A FOOT OR MORE FALL IN
CHEYENNE EITHER...BUT NEED TO SEE A FEW MORE MODEL RUNS TO BE SOLD
ON THAT SCENARIO. STAY TUNED AS THIS STORM APPEARS LIKELY TO GIVE US
QUITE A PUNCH. SNOW SHOULD FINALLY BEGIN TO DIMINISH BY SUN AFTN
AND/OR NIGHT AS THE LOW LIFTS INTO THE CENTRAL AND NORTHERN
PLAINS.
WITH THE LOW PRESSURE SYSTEM OPENING UP AND LIFTING OUT TO THE
NORTHEAST MONDAY...WE HAVE SOME LINGERING LIGHT SNOW SHOWERS IN
THE FORECAST FOR EARLY MONDAY MORNING...THEN WE SEE A CLEARING
AND WARMING TREND GOING THROUGH MIDWEEK. A RETURN OF DIURNAL
SHOWER/THUNDERSTORM CHANCES IS IN THE FORECAST BY LATE NEXT WEEK
AS WE SEE A NORTHWESTERLY FLOW ALOFT ON THE NORTHEAST SIDE OF A
4-CORNERS UPPER RIDGE. LOOKING JUST BEYOND THE 7 DAY FORECAST...
MODELS ARE SUGGESTING A MUCH WARMER AND DRIER WEEKEND FOR NEXT
WEEK.
&&
.AVIATION.../18Z ISSUANCE/
MOIST...UNSTABLE ATMOSPHERE THIS AFTERNOON AND EVENING. WILL
CONTINUE TO MAKE MENTION OF THUNDER...ESPECIALLY OVER AND SOUTH
OF I-80. BRIEF HEAVY RAIN LIKELY WITH ANY STORMS SOUTHEASTERLY
FLOW AT THE SURFACE THROUGH TONIGHT WITH REDEVELOPMENT OF MVFR TO
IFR CONDITIONS AT MOST LOCATIONS. FOG WILL BE MAIN THREAT WITH
AREAS OF LIGHT RAIN OR DRIZZLE. CIELINGS SHOULD ONCE AGAIN LIFT
MID TO LATE MORNING ON FRIDAY.
&&
.FIRE WEATHER...
ISSUED AT 526 AM MDT THU MAY 7 2015
THE COOL AND WET WEATHER PATTERN WILL CONTINUE THROUGH THE
WEEKEND...WITH FAIRLY HIGH CHANCES FOR MEASURABLE RAINFALL OR
SNOW. A STRONG STORM SYSTEM WILL IMPACT THE DISTRICTS THIS WEEKEND
WITH POTENTIALLY WIDESPREAD AND HEAVY PRECIPITATION AMOUNTS...AS
WELL AS GUSTY NORTHERLY WINDS. THIS SYSTEM WILL BE COLD
ENOUGH...WITH SNOW LEVELS DROPPING TO AROUND 5000 FEET. MINIMUM
RELATIVE HUMIDITY VALUES WILL REMAIN WELL ABOVE CRITICAL
THRESHOLDS THROUGH THE FORECAST PERIOD. A TREND TOWARD WARMER AND
DRIER CONDITIONS WILL COMMENCE BY TUESDAY.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WATCH FROM LATE FRIDAY NIGHT THROUGH SUNDAY
AFTERNOON FOR WYZ103-112-114-116.
NE...NONE.
&&
$$
UPDATE...WFOCYS
SHORT TERM...CLH/JG
LONG TERM...CLH
AVIATION...WFO CYS
FIRE WEATHER...JG